After we tried, I click the Subscribe, and fill in my credit card, but the payment failed.Something's not quite rightv4error.SUBSCRIPTION-81511

Glad to see you here in the Community, joey. 

Here are some of the possible reasons you’re seeing the error when updating the credit card info:

• Credit Card number is incorrect.
• Billing Address is invalid.
• The card-issuing bank won’t authorise the card electronically.

To see the complete list of the scenarios that causes the error, read through this article: Fix “My Subscription Payment Failed”. 

First, let's ensure to enter the correct Credit or Debit card number in the Payment Information page. Please make sure to access QBO and click Subscribe using a web browser. This is to ensure the payment will go through.

Second, enter the Billing Address details without special characters such as hyphens, commas and periods. You’ll have to verify if the billing address in QuickBooks is the same as the one shown on your credit card statement.

Third, I suggest contacting your credit card provider. From there, they can authorise your card to process payments online. Once done, go back and update your payment information for your subscription.

You can visit this resource hub: Billing Hub for Small Business. This link provides helpful articles on how to effectively manage your account, billing info, and subscription details.

I’m here anytime you have other concerns. Have a great day.