diff --git a/moto/ec2/responses/vpc_peering_connections.py b/moto/ec2/responses/vpc_peering_connections.py
index 1c0b6b983e8b..cae1f7df3569 100644
--- a/moto/ec2/responses/vpc_peering_connections.py
+++ b/moto/ec2/responses/vpc_peering_connections.py
@@ -202,7 +202,6 @@ def modify_vpc_peering_connection_options(self) -> str:
         <allowEgressFromLocalVpcToRemoteClassicLink>{{ vpc_pcx.accepter_options.AllowEgressFromLocalVpcToRemoteClassicLink or '' }}</allowEgressFromLocalVpcToRemoteClassicLink>
         <allowDnsResolutionFromRemoteVpc>{{ vpc_pcx.accepter_options.AllowDnsResolutionFromRemoteVpc or '' }}</allowDnsResolutionFromRemoteVpc>
       </peeringOptions>
-      <region>{{ vpc_pcx.peer_vpc.ec2_backend.region_name }}</region>
     </accepterVpcInfo>
     <status>
       <code>{{ vpc_pcx._status.code }}</code>
diff --git a/tests/test_ec2/test_vpc_peering.py b/tests/test_ec2/test_vpc_peering.py
index 36da5588917d..e0914a0ee3f6 100644
--- a/tests/test_ec2/test_vpc_peering.py
+++ b/tests/test_ec2/test_vpc_peering.py
@@ -1,3 +1,6 @@
+import os
+from unittest import mock
+
 import boto3
 import pytest
 
@@ -115,24 +118,45 @@ def test_vpc_peering_connections_delete_boto3():
 
 
 @mock_ec2
-def test_vpc_peering_connections_cross_region():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_vpc_peering_connections_cross_region(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering
-    vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
-    assert vpc_pcx_usw1.status["Code"] == "initiating-request"
-    assert vpc_pcx_usw1.requester_vpc.id == vpc_usw1.id
-    assert vpc_pcx_usw1.accepter_vpc.id == vpc_apn1.id
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
+        vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id,
+            PeerVpcId=vpc_apn1.id,
+            PeerRegion="ap-northeast-1",
+            PeerOwnerId=account2,
+        )
+
+    assert vpc_pcx_usw1["VpcPeeringConnection"]["Status"]["Code"] == "initiating-request"
+    assert vpc_pcx_usw1["VpcPeeringConnection"]["RequesterVpcInfo"]["VpcId"] == vpc_usw1.id
+    assert vpc_pcx_usw1["VpcPeeringConnection"]["AccepterVpcInfo"]["VpcId"] == vpc_apn1.id
+    # TODO add more assertions
+
     # test cross region vpc peering connection exist
-    vpc_pcx_apn1 = ec2_apn1.VpcPeeringConnection(vpc_pcx_usw1.id)
-    assert vpc_pcx_apn1.id == vpc_pcx_usw1.id
-    assert vpc_pcx_apn1.requester_vpc.id == vpc_usw1.id
-    assert vpc_pcx_apn1.accepter_vpc.id == vpc_apn1.id
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        vpc_pcx_apn1 = ec2_apn1.VpcPeeringConnection(vpc_pcx_usw1["VpcPeeringConnection"]["VpcPeeringConnectionId"])
+        assert vpc_pcx_apn1.id == vpc_pcx_usw1["VpcPeeringConnection"]["VpcPeeringConnectionId"]
+        assert vpc_pcx_apn1.requester_vpc.id == vpc_usw1.id
+        assert vpc_pcx_apn1.accepter_vpc.id == vpc_apn1.id
+
     # Quick check to verify the options have a default value
     accepter_options = vpc_pcx_apn1.accepter_vpc_info["PeeringOptions"]
     assert accepter_options["AllowDnsResolutionFromRemoteVpc"] is False
@@ -145,28 +169,47 @@ def test_vpc_peering_connections_cross_region():
 
 
 @mock_ec2
-def test_modify_vpc_peering_connections_accepter_only():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_modify_vpc_peering_connections_accepter_only(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    client = boto3.client("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        client = boto3.client("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering
-    vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
-    #
-    client.modify_vpc_peering_connection_options(
-        VpcPeeringConnectionId=vpc_pcx_usw1.id,
-        AccepterPeeringConnectionOptions={"AllowDnsResolutionFromRemoteVpc": True},
-    )
-    # Accepter options are different
-    vpc_pcx_usw1.reload()
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id,
+            PeerVpcId=vpc_apn1.id,
+            PeerRegion="ap-northeast-1",
+            PeerOwnerId=account2,
+        )
+
+        # modify peering connection options
+        client.modify_vpc_peering_connection_options(
+            VpcPeeringConnectionId=vpc_pcx_usw1.id,
+            AccepterPeeringConnectionOptions={"AllowDnsResolutionFromRemoteVpc": True},
+        )
+
+        # Accepter options are different
+        vpc_pcx_usw1.reload()
+
     accepter_options = vpc_pcx_usw1.accepter_vpc_info["PeeringOptions"]
     assert accepter_options["AllowDnsResolutionFromRemoteVpc"] is True
     assert accepter_options["AllowEgressFromLocalClassicLinkToRemoteVpc"] is False
     assert accepter_options["AllowEgressFromLocalVpcToRemoteClassicLink"] is False
+
     # Requester options are untouched
     requester_options = vpc_pcx_usw1.requester_vpc_info["PeeringOptions"]
     assert requester_options["AllowDnsResolutionFromRemoteVpc"] is False
@@ -175,30 +218,47 @@ def test_modify_vpc_peering_connections_accepter_only():
 
 
 @mock_ec2
-def test_modify_vpc_peering_connections_requester_only():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_modify_vpc_peering_connections_requester_only(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    client = boto3.client("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        client = boto3.client("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering
-    vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
-    #
-    client.modify_vpc_peering_connection_options(
-        VpcPeeringConnectionId=vpc_pcx_usw1.id,
-        RequesterPeeringConnectionOptions={
-            "AllowEgressFromLocalVpcToRemoteClassicLink": True,
-        },
-    )
-    # Requester options are different
-    vpc_pcx_usw1.reload()
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id,
+            PeerVpcId=vpc_apn1.id,
+            PeerRegion="ap-northeast-1",
+            PeerOwnerId=account2,
+        )
+        #
+        client.modify_vpc_peering_connection_options(
+            VpcPeeringConnectionId=vpc_pcx_usw1.id,
+            RequesterPeeringConnectionOptions={
+                "AllowEgressFromLocalVpcToRemoteClassicLink": True,
+            },
+        )
+        # Requester options are different
+        vpc_pcx_usw1.reload()
+
     requester_options = vpc_pcx_usw1.requester_vpc_info["PeeringOptions"]
     assert requester_options["AllowDnsResolutionFromRemoteVpc"] is False
     assert requester_options["AllowEgressFromLocalClassicLinkToRemoteVpc"] is False
     assert requester_options["AllowEgressFromLocalVpcToRemoteClassicLink"] is True
+
     # Accepter options are untouched
     accepter_options = vpc_pcx_usw1.accepter_vpc_info["PeeringOptions"]
     assert accepter_options["AllowDnsResolutionFromRemoteVpc"] is False
@@ -207,97 +267,159 @@ def test_modify_vpc_peering_connections_requester_only():
 
 
 @mock_ec2
-def test_modify_vpc_peering_connections_unknown_vpc():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_modify_vpc_peering_connections_unknown_vpc(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    client = boto3.client("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        client = boto3.client("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering
-    ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
-    #
-    with pytest.raises(ClientError) as ex:
-        client.modify_vpc_peering_connection_options(
-            VpcPeeringConnectionId="vpx-unknown", RequesterPeeringConnectionOptions={}
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id,
+            PeerVpcId=vpc_apn1.id,
+            PeerRegion="ap-northeast-1",
+            PeerOwnerId=account2,
         )
+
+        with pytest.raises(ClientError) as ex:
+            client.modify_vpc_peering_connection_options(
+                VpcPeeringConnectionId="vpx-unknown",
+                RequesterPeeringConnectionOptions={},
+            )
     err = ex.value.response["Error"]
     assert err["Code"] == "InvalidVpcPeeringConnectionId.NotFound"
     assert err["Message"] == "VpcPeeringConnectionID vpx-unknown does not exist."
 
 
 @mock_ec2
-def test_vpc_peering_connections_cross_region_fail():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_vpc_peering_connections_cross_region_fail(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering wrong region with no vpc
     with pytest.raises(ClientError) as cm:
-        ec2_usw1.create_vpc_peering_connection(
-            VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-2"
-        )
+        with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+            ec2_usw1.create_vpc_peering_connection(
+                VpcId=vpc_usw1.id,
+                PeerVpcId=vpc_apn1.id,
+                PeerRegion="ap-northeast-2",
+                PeerOwnerId=account2,
+            )
     assert cm.value.response["Error"]["Code"] == "InvalidVpcID.NotFound"
 
 
 @mock_ec2
-def test_describe_vpc_peering_connections_only_returns_requested_id():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_describe_vpc_peering_connections_only_returns_requested_id(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering
-    vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
-    vpc_pcx_usw2 = ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
-    # describe peering
-    ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
-    our_vpcx = [vpcx["VpcPeeringConnectionId"] for vpcx in retrieve_all(ec2_usw1)]
-    assert vpc_pcx_usw1.id in our_vpcx
-    assert vpc_pcx_usw2.id in our_vpcx
-    assert vpc_apn1.id not in our_vpcx
-
-    both_pcx = ec2_usw1.describe_vpc_peering_connections(
-        VpcPeeringConnectionIds=[vpc_pcx_usw1.id, vpc_pcx_usw2.id]
-    )["VpcPeeringConnections"]
-    assert len(both_pcx) == 2
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1", PeerOwnerId=account2,
+        )
+        vpc_pcx_usw2 = ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1", PeerOwnerId=account2,
+        )
 
-    one_pcx = ec2_usw1.describe_vpc_peering_connections(
-        VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
-    )["VpcPeeringConnections"]
-    assert len(one_pcx) == 1
+        # describe peering
+        ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
+        our_vpcx = [vpcx["VpcPeeringConnectionId"] for vpcx in retrieve_all(ec2_usw1)]
+
+        assert vpc_pcx_usw1.id in our_vpcx
+        assert vpc_pcx_usw2.id in our_vpcx
+        assert vpc_apn1.id not in our_vpcx
+
+        both_pcx = ec2_usw1.describe_vpc_peering_connections(
+            VpcPeeringConnectionIds=[vpc_pcx_usw1.id, vpc_pcx_usw2.id]
+        )["VpcPeeringConnections"]
+        assert len(both_pcx) == 2
+
+        one_pcx = ec2_usw1.describe_vpc_peering_connections(
+            VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
+        )["VpcPeeringConnections"]
+        assert len(one_pcx) == 1
 
 
 @mock_ec2
-def test_vpc_peering_connections_cross_region_accept():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_vpc_peering_connections_cross_region_accept(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering
-    vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1", PeerOwnerId=account2
+        )
+
     # accept peering from ap-northeast-1
-    ec2_apn1 = boto3.client("ec2", region_name="ap-northeast-1")
-    ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
-    acp_pcx_apn1 = ec2_apn1.accept_vpc_peering_connection(
-        VpcPeeringConnectionId=vpc_pcx_usw1.id
-    )
-    des_pcx_apn1 = ec2_usw1.describe_vpc_peering_connections(
-        VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
-    )
-    des_pcx_usw1 = ec2_usw1.describe_vpc_peering_connections(
-        VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
-    )
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.client("ec2", region_name="ap-northeast-1")
+        acp_pcx_apn1 = ec2_apn1.accept_vpc_peering_connection(
+            VpcPeeringConnectionId=vpc_pcx_usw1.id
+        )
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
+        des_pcx_apn1 = ec2_usw1.describe_vpc_peering_connections(
+            VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
+        )
+        des_pcx_usw1 = ec2_usw1.describe_vpc_peering_connections(
+            VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
+        )
+
     assert acp_pcx_apn1["VpcPeeringConnection"]["Status"]["Code"] == "active"
     assert (
         acp_pcx_apn1["VpcPeeringConnection"]["AccepterVpcInfo"]["Region"]
@@ -328,102 +450,190 @@ def test_vpc_peering_connections_cross_region_accept():
 
 
 @mock_ec2
-def test_vpc_peering_connections_cross_region_reject():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_vpc_peering_connections_cross_region_reject(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering
-    vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1", PeerOwnerId=account2
+        )
+
     # reject peering from ap-northeast-1
-    ec2_apn1 = boto3.client("ec2", region_name="ap-northeast-1")
-    ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
-    rej_pcx_apn1 = ec2_apn1.reject_vpc_peering_connection(
-        VpcPeeringConnectionId=vpc_pcx_usw1.id
-    )
-    des_pcx_apn1 = ec2_usw1.describe_vpc_peering_connections(
-        VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
-    )
-    des_pcx_usw1 = ec2_usw1.describe_vpc_peering_connections(
-        VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
-    )
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.client("ec2", region_name="ap-northeast-1")
+        rej_pcx_apn1 = ec2_apn1.reject_vpc_peering_connection(
+            VpcPeeringConnectionId=vpc_pcx_usw1.id
+        )
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
+        des_pcx_apn1 = ec2_usw1.describe_vpc_peering_connections(
+            VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
+        )
+        des_pcx_usw1 = ec2_usw1.describe_vpc_peering_connections(
+            VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
+        )
     assert rej_pcx_apn1["Return"] is True
     assert des_pcx_apn1["VpcPeeringConnections"][0]["Status"]["Code"] == "rejected"
     assert des_pcx_usw1["VpcPeeringConnections"][0]["Status"]["Code"] == "rejected"
 
 
 @mock_ec2
-def test_vpc_peering_connections_cross_region_delete():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_vpc_peering_connections_cross_region_delete(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering
-    vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
-    # reject peering from ap-northeast-1
-    ec2_apn1 = boto3.client("ec2", region_name="ap-northeast-1")
-    ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
-    del_pcx_apn1 = ec2_apn1.delete_vpc_peering_connection(
-        VpcPeeringConnectionId=vpc_pcx_usw1.id
-    )
-    des_pcx_apn1 = ec2_usw1.describe_vpc_peering_connections(
-        VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
-    )
-    des_pcx_usw1 = ec2_usw1.describe_vpc_peering_connections(
-        VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
-    )
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1", PeerOwnerId=account2
+        )
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        # reject peering from ap-northeast-1
+        ec2_apn1 = boto3.client("ec2", region_name="ap-northeast-1")
+        del_pcx_apn1 = ec2_apn1.delete_vpc_peering_connection(
+            VpcPeeringConnectionId=vpc_pcx_usw1.id
+        )
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
+        des_pcx_apn1 = ec2_usw1.describe_vpc_peering_connections(
+            VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
+        )
+        des_pcx_usw1 = ec2_usw1.describe_vpc_peering_connections(
+            VpcPeeringConnectionIds=[vpc_pcx_usw1.id]
+        )
+
     assert del_pcx_apn1["Return"] is True
     assert des_pcx_apn1["VpcPeeringConnections"][0]["Status"]["Code"] == "deleted"
     assert des_pcx_usw1["VpcPeeringConnections"][0]["Status"]["Code"] == "deleted"
 
 
 @mock_ec2
-def test_vpc_peering_connections_cross_region_accept_wrong_region():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_vpc_peering_connections_cross_region_accept_wrong_region(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering
-    vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1", PeerOwnerId=account2
+        )
 
     # accept wrong peering from us-west-1 which will raise error
-    ec2_apn1 = boto3.client("ec2", region_name="ap-northeast-1")
-    ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
-    with pytest.raises(ClientError) as cm:
-        ec2_usw1.accept_vpc_peering_connection(VpcPeeringConnectionId=vpc_pcx_usw1.id)
-    assert cm.value.response["Error"]["Code"] == "OperationNotPermitted"
-    exp_msg = f"Incorrect region (us-west-1) specified for this request.VPC peering connection {vpc_pcx_usw1.id} must be accepted in region ap-northeast-1"
-    assert cm.value.response["Error"]["Message"] == exp_msg
+    # only applicable for cross-region intra-account peering.
+    if account1 == account2:
+        with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+            ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
+            with pytest.raises(ClientError) as cm:
+                ec2_usw1.accept_vpc_peering_connection(VpcPeeringConnectionId=vpc_pcx_usw1.id)
+
+        assert cm.value.response["Error"]["Code"] == "OperationNotPermitted"
+        exp_msg = f"Incorrect region (us-west-1) specified for this request. VPC peering connection {vpc_pcx_usw1.id} must be accepted in region ap-northeast-1"
+        assert cm.value.response["Error"]["Message"] == exp_msg
+
+    # Ensure accepting peering from requester account raises
+    # only applicable for cross-region inter-account peering.
+    if account1 != account2:
+        with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+            ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
+            with pytest.raises(ClientError) as cm:
+                ec2_usw1.accept_vpc_peering_connection(VpcPeeringConnectionId=vpc_pcx_usw1.id)
+
+        assert cm.value.response["Error"]["Code"] == "OperationNotPermitted"
+        exp_msg = f"User ({account1}) cannot accept peering {vpc_pcx_usw1.id}"
+        assert cm.value.response["Error"]["Message"] == exp_msg
 
 
 @mock_ec2
-def test_vpc_peering_connections_cross_region_reject_wrong_region():
+@pytest.mark.parametrize(
+    "account1,account2",
+    [
+        pytest.param("111111111111", "111111111111", id="within account"),
+        pytest.param("111111111111", "222222222222", id="across accounts"),
+    ],
+)
+def test_vpc_peering_connections_cross_region_reject_wrong_region(account1, account2):
     # create vpc in us-west-1 and ap-northeast-1
-    ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
-    vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
-    ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
-    vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        ec2_usw1 = boto3.resource("ec2", region_name="us-west-1")
+        vpc_usw1 = ec2_usw1.create_vpc(CidrBlock="10.90.0.0/16")
+
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account2}):
+        ec2_apn1 = boto3.resource("ec2", region_name="ap-northeast-1")
+        vpc_apn1 = ec2_apn1.create_vpc(CidrBlock="10.20.0.0/16")
+
     # create peering
-    vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
-        VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1"
-    )
-    # reject wrong peering from us-west-1 which will raise error
-    ec2_apn1 = boto3.client("ec2", region_name="ap-northeast-1")
-    ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
-    with pytest.raises(ClientError) as cm:
-        ec2_usw1.reject_vpc_peering_connection(VpcPeeringConnectionId=vpc_pcx_usw1.id)
-    assert cm.value.response["Error"]["Code"] == "OperationNotPermitted"
-    exp_msg = f"Incorrect region (us-west-1) specified for this request.VPC peering connection {vpc_pcx_usw1.id} must be accepted or rejected in region ap-northeast-1"
-    assert cm.value.response["Error"]["Message"] == exp_msg
+    with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+        vpc_pcx_usw1 = ec2_usw1.create_vpc_peering_connection(
+            VpcId=vpc_usw1.id, PeerVpcId=vpc_apn1.id, PeerRegion="ap-northeast-1", PeerOwnerId=account2
+        )
+
+    # reject wrong peering from us-west-1 which will raise error.
+    # only applicable for cross-region intra-account peering.
+    if account1 == account2:
+        with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+            ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
+            with pytest.raises(ClientError) as cm:
+                ec2_usw1.reject_vpc_peering_connection(VpcPeeringConnectionId=vpc_pcx_usw1.id)
+
+        assert cm.value.response["Error"]["Code"] == "OperationNotPermitted"
+        exp_msg = f"Incorrect region (us-west-1) specified for this request. VPC peering connection {vpc_pcx_usw1.id} must be accepted or rejected in region ap-northeast-1"
+        assert cm.value.response["Error"]["Message"] == exp_msg
+
+    # Ensure rejecting peering from requester account raises
+    # only applicable for cross-region inter-account peering.
+    if account1 != account2:
+        with mock.patch.dict(os.environ, {"MOTO_ACCOUNT_ID": account1}):
+            ec2_usw1 = boto3.client("ec2", region_name="us-west-1")
+            with pytest.raises(ClientError) as cm:
+                ec2_usw1.reject_vpc_peering_connection(VpcPeeringConnectionId=vpc_pcx_usw1.id)
+
+        assert cm.value.response["Error"]["Code"] == "OperationNotPermitted"
+        exp_msg = f"User ({account1}) cannot reject peering {vpc_pcx_usw1.id}"
+        assert cm.value.response["Error"]["Message"] == exp_msg
 
 
 def retrieve_all(client):