Hi accounts@novalux
If you're expecting to receive an invoice at a later date, enter this as a Bill Payment in QBO.
(when logged in, go to https://app.qbo.intuit.com/app/billpayment)
You don't need to mark the Payment against a Bill. Instead, this will record a credit on the supplier's register that you can subsequently use to clear the Bill in QBO.
Alternatively, you can enter as a Cheque (or Expense if paid on Credit Card).
Enter against the Supplier's Name. Category = Accounts Payable. VAT = NoVAT
This will create the same credit on the Supplier's register that you can subsequently use to clear the Bill in QBO.
Hope this helps.