i have paid an invoice twice in error how do i enter the 2nd payment into quickbooks with no bill to associate it with?

Hi, Welcome to the Community, To show a payment to a supplier where there is no bill to associate it with,

you can create a cheque or an expense for the amount overpaid, select the supplier date and in the account section in account details select the creditors account and then when you have a bill for that supplier you can link it to that by selecting make payment and the expense/cheque overpayment will be there for you to use