Let me help you in updating your vendor's bank account information, @Anonymous.

For us to update the vendor's account number, we need to change the payment method from Online Bill Pay to paper checks. Then, toggle it back within QuickBooks Online. Once reverted, the system will ask you to re-enter their bank account information or sending them a new request.

Here's how:

1. On the left panel, click Expenses.
2. Go to the Vendors tab.
3. Search and click the vendor.
4. There will be a box at the top saying BILL PAY ONLINE, click the CHANGE PAYMENT METHOD TO CHECK link.
5. Confirm action.
6. It'll be asking you to invite the vendor to online bill pay, click the link and enter new bank info or send a new invite to the vendor.

If you're still unable to update this information, I recommend reaching out to our Support Specialists. This way, they can take a closer to your account and provide you another detailed option to update the account.

You can reach them through these steps:

1. Click the Help icon, then select Contact us.
2. Enter "How to edit a vendor's bank transfer account number?" on the description field.
3. Hit Let’s talk.
4. Choose Start messaging or Get a callback.

You can also check out our support hours to make sure we address your concerns on time.

You'll also want to read this article to learn more about Online Bill Pay. This will provide you answers to frequently asked questions about it.

Please keep in touch with me here should you need any further assistance regarding updating the bank account info. The Community always has your back.