From 72aac20ef737a1101ed194479eef463d3781be3f Mon Sep 17 00:00:00 2001
From: Stefan Schmidt <stschmidt@google.com>
Date: Sat, 17 Jun 2017 01:53:12 +0200
Subject: [PATCH] Allow unlinking of billing account. Closes #133

---
 CHANGELOG.md                      | 1 +
 google/resource_google_project.go | 5 +++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a0eff33ff9c..3b77cb2ec29 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,3 +14,4 @@ IMPROVEMENTS:
 BUG FIXES:
 
 * Changed `google_compute_instance_group_manager` `target_size` default to 0 [GH-65]
+* Allow unlinking of billing account [GH-133]
diff --git a/google/resource_google_project.go b/google/resource_google_project.go
index 4e71d0d46bb..68ab2dc68af 100644
--- a/google/resource_google_project.go
+++ b/google/resource_google_project.go
@@ -200,8 +200,9 @@ func resourceGoogleProjectUpdate(d *schema.ResourceData, meta interface{}) error
 	// Billing account has changed
 	if ok := d.HasChange("billing_account"); ok {
 		name := d.Get("billing_account").(string)
-		ba := cloudbilling.ProjectBillingInfo{
-			BillingAccountName: "billingAccounts/" + name,
+		ba := cloudbilling.ProjectBillingInfo{}
+		if name != "" {
+			ba.BillingAccountName = "billingAccounts/" + name
 		}
 		_, err = config.clientBilling.Projects.UpdateBillingInfo(prefixedProject(pid), &ba).Do()
 		if err != nil {