Article 21
1. The following deductions may be made from payment requests, invoices or statements, which shall then be passed for payment of the net amount: (a) penalties imposed on parties to procurement contracts or beneficiaries of a grant; (b) discounts, refunds and rebates on individual invoices and payment requests; (c) interest generated by pre-financing payments. 2. The cost of products or services provided to Europol shall be charged to the budget for the full ex-tax amount, where they incorporate taxes refunded: (a) either by the Member States pursuant to the Protocol on Privileges and Immunities of the European Communities, by the Host State on the basis of the Seat Agreement or on the basis of other relevant agreements; (b) or by a Member State or non-member country on the basis of other relevant agreements. Any national taxes temporarily borne by Europol under the first subparagraph shall be entered in a suspense account until they are refunded by the State concerned. 3. Any negative balance shall be entered in the budget as expenditure. 4. Adjustments may be made in respect of exchange differences occurring in the implementation of the budget. The final gain or loss shall be included in the balance for the year.