Requirements for cancellation

To cancel your account, you'll need:

Administrative access to your account

Billing set up for your account

If you have a manager account and want to cancel one of your managed accounts, keep in mind the following requirements:

You’ll need administrative access to your manager account

Your manager account needs to have created the managed account you’d like to cancel

That managed account can have no other users with administrative access
 

Read About canceling managed accounts to learn more.
https://support.google.com/google-ads/answer/7527351

How to cancel your account

1. Sign into your Google Ads account.

2. Click the tools icon   in the upper right corner. 

3. Under “Setup,” click Preferences.

4. Click the Account Status section to expand it.

5. Click Cancel my account. 

Tip from TNW Creations: Screenshot your cancellation.... you should receive an email confirmation but if you don't, you will want to have data you cancelled. Don't close the window without it. Should you need to show this to your bank, you will have proof.

After your account is canceled

The following will take place after canceling your account:

All remarketing lists that are owned by the canceled account, including Customer Match, will be set to “Closed,” preventing new users from being added to these lists.

Tip from TNW Creations: As mentioned above, you should receive an email confirmation of your closed Google Ads account. When you do, print a digital and hardcopy. Keep it for your records.

In an effort to remove your data, the following will take place about a month after account cancellation:

All remarketing lists that are owned by the canceled account, including Customer Match, will have their membership duration updated to 1 day. This action will remove all users from these lists.

Once the users are removed, lists that are shared with other accounts will no longer be usable for those accounts.

Any parameters for dynamic remarketing will be deleted.

If you have any refundable credit left in your canceled account, you should receive a refund within 4-12 weeks. Learn more about managing billing after canceling your Google Ads account

Problems canceling your account

If you don't see the option to cancel your account, you may not be eligible to cancel it. Review "Requirements for cancellation” above.

If your administrative access user left the company, and you want to cancel your account, collect your Customer ID, sign-in email address, account billing information, and contact Google Ads support.

https://support.google.com/google-ads/gethelp