You are under the obligation as soon as you raise an invoice with one of your clients to pay on the value-added tax charge included in your invoice to the Tax and Customs Administration.
The current economic climate is one in which it is not uncommon for clients not to pay their bills (in their entirety). This gives you the option of asking the Tax and Customs Administration for a proportionate refund.
Refunds are made strictly on request. It is not permissible in the context of the value-added tax return to set off the refundable value-added tax against the value-added tax that is due and payable by yourself. You will receive separate notification of the refund from the Tax and Customs Administration.
It is important that you should be able to prove that your client has failed to pay the invoice and can no longer be expected belatedly to settle up. You have a degree of discretion where this is concerned.
The petition for a refund is required to be made within a one month term of the date as at which the outstanding invoice was first established as having been rendered irrecoverable.