diff --git a/config/locales/en.yml b/config/locales/en.yml
index 1ff99bf4c..67d879f8f 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -165,6 +165,7 @@ en:
       feature_unavailable: MFA feature is not available. Please configure encryption keys.
     billing:
       invalid_currency: Invalid billing currency
+      currency_locked: Billing currency cannot be changed after billing has been set up
     topup:
       credits_required: Credits amount is required
       invalid_credits: Invalid credits amount
diff --git a/enterprise/app/controllers/enterprise/api/v1/accounts_controller.rb b/enterprise/app/controllers/enterprise/api/v1/accounts_controller.rb
index 53f95c2a8..19f516522 100644
--- a/enterprise/app/controllers/enterprise/api/v1/accounts_controller.rb
+++ b/enterprise/app/controllers/enterprise/api/v1/accounts_controller.rb
@@ -12,6 +12,8 @@ class Enterprise::Api::V1::AccountsController < Api::BaseController
   end
 
   def select_billing_currency
+    return render_could_not_create_error(I18n.t('errors.billing.currency_locked')) if stripe_customer_id.present?
+
     currency = Enterprise::Billing::Currencies.normalize(params[:currency])
     return render_could_not_create_error(I18n.t('errors.billing.invalid_currency')) unless Enterprise::Billing::Currencies.supported?(currency)