You can have payments or similar transactions (eg overpayments, prepayments, reversed invoices, Adjustment Notes etc) that result in unallocated amounts on a supplier's account. Because Grain Trader uses an Open Item accounting model, these amounts remain available until specifically allocated to one or more invoice transactions. The process of allocating these amounts to invoices is called linking.

1. Select the Supplier against whom you want to record a payment
2. Select the invoice (or similar) transaction and start the linking process
3. Select the payment (or similar) transaction and complete the linking process
4. The linking process can also be reversed (applies to Grain Trader versions 3.2.7 and later only)

Click Supplier on the Shortcut Bar to display the Select Supplier window, then select the supplier:

On the Transactions tab, select the Invoice or similar transaction, then click the Link button. Invoice-type transactions include all types of invoices or adjustment notes that result in you owing the supplier money. If this transaction cannot be used to start the linking process (eg if it is an invoice that does not have an outstanding balance, or it is a payment-type transaction) you will be advised and the linking process will not proceed.

Select the Payment or similar transaction and click the Link button again. Payment-type transactions include payments, prepayments, reversed invoices or adjustment notes that result in a reduction in the amount you owe the supplier. If this transaction cannot be used to complete the linking process (eg if it is a payment that has already been fully allocated, or is an invoice-type transaction) you will be advised and the linking process will not proceed.

If the linking was successful the two linked transactions will be displayed consecutively in the transactions grid and the bracketing will indicate they are linked. If there is still an outstanding balance on the invoice-type transaction it, together with all its linked transactions, will remain on the transactions grid for the current month, every month until future payments are linked to it. When the outstanding balance becomes zero the whole group of linked transactions will become historical and will not appear in the transactions grid for any month after the month of the last linked transaction.

Transactions that have previously been linked can be unlinked. When you select the payment-type linked transaction the Link button becomes Unlink.

If you click the Unlink button the link will be reversed, ie the invoice amount outstanding will be increased by the payment amount, and the payment amount will become unallocated. If there is another unallocated amount from the same payment transaction the two payment transactions will be merged into one.