diff --git a/app/models/enterprise.rb b/app/models/enterprise.rb
index 049eefef65..5ef1a58ba1 100644
--- a/app/models/enterprise.rb
+++ b/app/models/enterprise.rb
@@ -133,6 +133,9 @@ class Enterprise < ApplicationRecord
               message: Spree.t('errors.messages.invalid_instagram_url')
             }, allow_blank: true
   validate :validate_white_label_logo_link
+  validates :external_billing_id,
+            format: { with: /\A\S+\z/ },
+            allow_blank: true
 
   before_validation :initialize_permalink, if: lambda { permalink.nil? }
   before_validation :set_unused_address_fields
diff --git a/spec/models/enterprise_spec.rb b/spec/models/enterprise_spec.rb
index 7f790e096f..5464604837 100644
--- a/spec/models/enterprise_spec.rb
+++ b/spec/models/enterprise_spec.rb
@@ -415,6 +415,18 @@ RSpec.describe Enterprise do
         expect(e).not_to be_valid
       end
     end
+
+    describe "external_billing_id" do
+      it "validates the external_billing_id attribute" do
+        e = build(:enterprise, external_billing_id: '123456')
+        expect(e).to be_valid
+      end
+
+      it "does not validate the external_billing_id attribute with spaces" do
+        e = build(:enterprise, external_billing_id: '123 456')
+        expect(e).not_to be_valid
+      end
+    end
   end
 
   describe "serialisation" do