Suppose a VAT entrepreneur auctions goods and services via a website. He then owes VAT the moment he hands the winning consumer a voucher to be redeemed. Even if not everyone redeems such coupons.
Main rule indebtedness of sales tax on invoice
If a VAT entrepreneur has to issue an invoice because of a service rendered, he is in principle liable to pay turnover tax at the time when he issues the invoice. Does the entrepreneur not issue the invoice on time? In that case, he owes the turnover tax at the latest when he should have issued the invoice. These rules do not apply in the case of reverse charge. In that case, the purchaser of the performance will owe the turnover tax at the time when the entrepreneur provides the service. Suppose now that the entrepreneur receives (partial) compensation for his performance before he has issued or should have issued an invoice or before the service with reverse charge VAT has been provided. In that case, the turnover tax is due at the time of this (partial) receipt.
Source Taxence
