Updating subsciption payment card

Hi  Sean, thanks for joining us here on the Community - are you using a UK or Irish QuickBooks subscription, and is it the Primary Admin of the account attempting to update payment details? 

Irish Quickbooks subscription and primary user

Error 81819 is appearing

Thank you for visiting us here in Community, @Sean Dunleavy.

 
We can perform some steps to get the Billing and Subscription window working
Sign in to your QuickBooks Online (QBO) account using a private or Incognito window to see if this is a browser issue. Then go back to the Billing and Subscription page and try again.

 
If you can access it without getting an error message, clear your browser's cache to get rid of the temporary files, or switch to another supported browser.

 
If the same thing occurs again, please get in touch with our Customer Service Department. They'll look into what's causing the problem further. They can also assist you with updating your payment information in QBO.

Here's how to reach them:
 

1. Click Help on the top menu.
2. Choose Contact us.
3. Enter can't access Billing and Subscription page in the What can we help you with? field.
4. Click Let's talk.
5. Choose Start an email to connect with us.

 
I added articles here about updating billing information and subscription for your reference:

• Manage billing, payment, and subscription info in QuickBooks Online.
• Update billing, subscription, and firm info in QuickBooks Online Accountant.

If you require anything else in QBO, please comment to this thread. I'm always willing to assist.