Cancel a bill you already approved

Cancelling a bill reverses the accounting it posted, without deleting anything. The original entry stays in your books and a matching reversing entry is added beside it, so the history of what happened is still readable a year later.

On Ledger › Expenses, open the bill.
Click Cancel bill.
Give a reason if you want one, then confirm.

The bill is marked cancelled, with the date and your reason shown on it.

If you had already paid the bill

The payment is left exactly as it is. The money really did leave your bank account, and pretending otherwise would break your next reconciliation.

Instead, the amount you had paid becomes a credit with that supplier: they are holding your money. It shows on your balance sheet under Vendor Credits, and against that supplier on Ledger › Expenses › Vendors.

This is the mirror of what happens when a customer overpays you. Your books stay tied out either way: the bill no longer sits in Accounts Payable, and the cash you paid is recorded as something owed back to you rather than quietly disappearing.

Using up a supplier credit

Once the credit exists you have two ways to clear it.

Put it toward another bill from the same supplier. Open any of their open bills and apply the credit to it. It covers part or all of the balance, and the bill's outstanding amount drops by what you applied. You can apply it across several bills until it runs out. A credit can only go to bills from the supplier holding it.
They send the money back. When the refund lands in your bank, find the deposit on Ledger › Banking › Transactions and record it as a vendor credit refund against that supplier. Their credit goes back to zero and the money is in your bank.

Note which direction each one is. A customer credit is refunded on a withdrawal, because you are sending money out. A supplier credit is refunded on a deposit, because they are sending yours back.

Both work on bank lines in your book's own currency. A foreign-currency line is refused rather than recorded at the wrong value.

Seeing where a credit came from and what it paid for

Go to Ledger › Expenses › Vendors and click the supplier's row to open it. A Credit history section lists every movement: the cancelled bill that created the credit, each bill you applied it to, and any refund that came back. Each row shows the date, the amount, and the balance left afterwards, newest first, so the top row's balance is what the supplier is holding right now. Click any document in the list to open the bill or the bank line behind it.

The section covers the whole relationship, not the period you have selected, because a credit balance is a running total rather than a figure for a date range. It appears only for suppliers that have actually had a credit, and it stays available after a credit is fully spent, which is when "where did it go" is usually the question.

If TALISK_HQ refuses because the bill has no supplier name

A credit has to belong to somebody. If you cancel a bill that has been paid but carries no supplier name, TALISK_HQ refuses and tells you so, rather than creating a credit that nothing can be attributed to and nobody could ever use.

Open the bill, fill in the supplier name, save, then cancel it. An unpaid bill with no supplier name cancels normally, because there is no credit to attribute.

Cancel or discard

Cancel keeps the document and reverses its accounting. Use it for a real bill that genuinely posted and now needs undoing, such as an order you returned or an invoice the supplier reissued.

Discard removes the document from your books entirely, and can be undone. Use it for something that should never have been there: a duplicate, a quote mistaken for a bill, or a receipt filed to the wrong book.

If a bill was real and you paid it, cancel is almost always the one you want. Discard erases the trail; cancel leaves one.