Article 55 stipulates the conditions under which a Taxable Person must issue a Tax Invoice or a similar document. This obligation applies to the supply of goods or services, including deemed supplies as specified in Article 8, and upon the receipt of any consideration before the supply date. Member States may exempt a Taxable Person from issuing invoices for exempted supplies, provided these do not involve Intra-GCC transactions. Subject to Article 56, Member States can also permit the issuance of summary tax invoices, consolidating all supplies to a single customer within one month. The article mandates that all Member States must accept invoices in both paper and electronic formats, according to their own prescribed conditions.