I have a company with whom I both buy and sell. I need to offset one of my invoices against one of theirs as they tell me that they will only pay the balance of the two.

Hello Jennyandinchristi

When it comes to paying off your invoice and their bill you will need to use a journal entry

You can go to the plus symbol and then journal entry to create this.

It is a case of creating  2 lines one to debtors and the amount(under the credits side) with the customer name selected and then the other to creditors and the amount(under the debit side) selecting the supplier name on that line

You can then go to the invoice and select receive payment and use the journal and the same on the supplier and make a payment on the bill

If you need to enter differing amounts the other option would be doing two separate journals and using a contra account which we can go through as an alternative

Let us know how you get on

Thanks

Emma