diff --git a/organization_invitation.go b/organization_invitation.go
index f7c8916..b0198ea 100644
--- a/organization_invitation.go
+++ b/organization_invitation.go
@@ -22,6 +22,7 @@ type OrganizationInvitation struct {
 	Status                 string                  `json:"status"`
 	PublicMetadata         json.RawMessage         `json:"public_metadata"`
 	PrivateMetadata        json.RawMessage         `json:"private_metadata"`
+	ExpiresAt              *int64                  `json:"expires_at,omitempty"`
 	CreatedAt              int64                   `json:"created_at"`
 	UpdatedAt              int64                   `json:"updated_at"`
 }
diff --git a/organizationinvitation/client.go b/organizationinvitation/client.go
index fdf949c..d2bfb7f 100644
--- a/organizationinvitation/client.go
+++ b/organizationinvitation/client.go
@@ -34,6 +34,7 @@ type CreateParams struct {
 	PublicMetadata  *json.RawMessage `json:"public_metadata,omitempty"`
 	PrivateMetadata *json.RawMessage `json:"private_metadata,omitempty"`
 	OrganizationID  string           `json:"-"`
+	ExpiresInDays   *int64           `json:"expires_in_days,omitempty"`
 }
 
 // Create creates and sends an invitation to join an organization.
diff --git a/organizationinvitation/client_test.go b/organizationinvitation/client_test.go
index 62450f4..cd5edc1 100644
--- a/organizationinvitation/client_test.go
+++ b/organizationinvitation/client_test.go
@@ -22,8 +22,8 @@ func TestOrganizationInvitationClientCreate(t *testing.T) {
 	config.HTTPClient = &http.Client{
 		Transport: &clerktest.RoundTripper{
 			T:      t,
-			In:     json.RawMessage(fmt.Sprintf(`{"email_address":"%s"}`, emailAddress)),
-			Out:    json.RawMessage(fmt.Sprintf(`{"id":"%s","email_address":"%s","organization_id":"%s"}`, id, emailAddress, organizationID)),
+			In:     json.RawMessage(fmt.Sprintf(`{"email_address":"%s", "expires_in_days": 1}`, emailAddress)),
+			Out:    json.RawMessage(fmt.Sprintf(`{"id":"%s","email_address":"%s","organization_id":"%s", "expires_at": 1}`, id, emailAddress, organizationID)),
 			Method: http.MethodPost,
 			Path:   "/v1/organizations/" + organizationID + "/invitations",
 		},
@@ -32,11 +32,13 @@ func TestOrganizationInvitationClientCreate(t *testing.T) {
 	invitation, err := client.Create(context.Background(), &CreateParams{
 		OrganizationID: organizationID,
 		EmailAddress:   clerk.String(emailAddress),
+		ExpiresInDays:  clerk.Int64(1),
 	})
 	require.NoError(t, err)
 	require.Equal(t, id, invitation.ID)
 	require.Equal(t, organizationID, invitation.OrganizationID)
 	require.Equal(t, emailAddress, invitation.EmailAddress)
+	require.Equal(t, int64(1), *invitation.ExpiresAt)
 }
 
 func TestOrganizationInvitationClientCreate_Error(t *testing.T) {
@@ -74,7 +76,7 @@ func TestOrganizationInvitationClientList(t *testing.T) {
 	config.HTTPClient = &http.Client{
 		Transport: &clerktest.RoundTripper{
 			T:      t,
-			Out:    json.RawMessage(fmt.Sprintf(`{"data":[{"id":"%s","object":"organization_invitation","email_address":"string","role":"string","organization_id":"%s","status":"string","public_metadata":{},"private_metadata":{},"created_at":0,"updated_at":0}],"total_count":1}`, id, organizationID)),
+			Out:    json.RawMessage(fmt.Sprintf(`{"data":[{"id":"%s","object":"organization_invitation","email_address":"string","role":"string","organization_id":"%s","status":"string","public_metadata":{},"private_metadata":{},"expires_at":1,"created_at":0,"updated_at":0}],"total_count":1}`, id, organizationID)),
 			Method: http.MethodGet,
 			Path:   "/v1/organizations/" + organizationID + "/invitations",
 			Query: &url.Values{
@@ -95,6 +97,7 @@ func TestOrganizationInvitationClientList(t *testing.T) {
 	require.Len(t, response.OrganizationInvitations, 1)
 	require.Equal(t, id, response.OrganizationInvitations[0].ID)
 	require.Equal(t, organizationID, response.OrganizationInvitations[0].OrganizationID)
+	require.Equal(t, int64(1), *response.OrganizationInvitations[0].ExpiresAt)
 	require.Equal(t, int64(1), response.TotalCount)
 }
 
@@ -131,7 +134,7 @@ func TestOrganizationInvitationClientGet(t *testing.T) {
 	config.HTTPClient = &http.Client{
 		Transport: &clerktest.RoundTripper{
 			T:      t,
-			Out:    json.RawMessage(fmt.Sprintf(`{"id":"%s","object":"organization_invitation","email_address":"string","role":"string","role_name":"string","organization_id":"%s","status":"string","public_metadata":{},"private_metadata":{},"created_at":0,"updated_at":0}`, id, organizationID)),
+			Out:    json.RawMessage(fmt.Sprintf(`{"id":"%s","object":"organization_invitation","email_address":"string","role":"string","role_name":"string","organization_id":"%s","status":"string","public_metadata":{},"private_metadata":{},"expires_at": 1,"created_at":0,"updated_at":0}`, id, organizationID)),
 			Method: http.MethodGet,
 			Path:   "/v1/organizations/" + organizationID + "/invitations/" + id,
 		},
@@ -146,6 +149,7 @@ func TestOrganizationInvitationClientGet(t *testing.T) {
 	require.Equal(t, organizationID, response.OrganizationID)
 	require.Equal(t, "string", response.RoleName)
 	require.Equal(t, "string", response.Role)
+	require.Equal(t, int64(1), *response.ExpiresAt)
 }
 
 func TestOrganizationInvitationClientGet_Error(t *testing.T) {