A till receipt is not an invoice: when you can deduct it and when you can't
You have lunch with a client, pay 48 euros and tuck the receipt into your wallet with a sense of duty done. Three months later, doing your quarterly return, that crumpled piece of paper is worth rather less than you thought: you can deduct the expense, but not the VAT. And not because the receipt is faulty, but because it’s missing one line you can only ask for at the moment you pay.