Nope, once a Google Ads account number (also called the Customer ID) is created, you can’t change it. It’s permanently tied to that account.
Think of it like a bank account number or a phone number, it’s unique, and Google uses it to track everything: billing, history, campaigns, permissions, etc.
What you can do instead:
If you need a different account for structure, currency, or region reasons, just create a new Google Ads account under your existing Google login.
If you manage multiple accounts, consider using a Google Ads Manager Account (MCC) to keep everything organized. This lets you switch between accounts easily without logging in/out.
Common reasons people want to change their account number:
Wrong currency or time zone (can’t be edited once set)
Account tied to the wrong business/client
Want a “clean slate” with no history
In those cases, creating a new account is usually the way to go.