Grounds and deadlines come from Art. 96, Art. 97a, Art. 99 and Art. 100 of the Bulgarian VAT Act; the effects of a cross-border registration from Art. 70(4) and Art. 113(9). This tool is general information as at August 2026 and not advice on your file — whether a particular supply falls within Art. 97a depends on its place of supply and on your supplier's status. The full explanation, with the article references, is on the accounting and VAT page.