How do I associate an accounts payable account to a supplier, so that when I register the invoice it stays in that account and not in Account Payable.

Hello there,

I understand that you are trying to assign a separate AP account for your supplier. While you can create multiple Accounts Payable accounts in your Chart of Accounts, QuickBooks Online will not allow you to use them instead, it only uses the initially set up account for tracking bills. With that, it is generally recommended to maintain one AP account.

For more details, refer to this article: Warning: You cannot use more than one AR or AP account in the same transaction.

If you need to separate your accounts, I recommend checking out the suggestions listed here: How to group Accounts Receivable or Accounts Payable account types.

I hope this information helps. If you have any further questions or concerns, please don't hesitate to ask. I'm determined to ensure your success. Hope you have a great day ahead!