Generally, any supplier (a taxable person, registered for VAT purposes) has to issue an invoice for each effected supply. The stamp and the signature are not obligatory, provided that the invoice contains certain wording. Furthermore, the issuance of invoice is not obligatory in case when the recipient is a non-taxable individual or in case of free of charge supplies.
Invoices can be issued also electronically, subject to specific requirements. Following the current interpretation of the Bulgarian revenue authorities, an electronic invoice is accepted by the revenue authorities as a valid tax document where the authenticity of the origin and the integrity of its content are guaranteed by universal electronic signature (such electronic signatures can be obtained from a Bulgarian licensed supplier). Furthermore, the recipient must have accepted to receive electronic invoices and must confirm the receipt of each electronic invoice he has received.
In practice, electronic invoicing is still not widely applied in Bulgaria due to the lack of sufficient clarity and particularly in cases where the customers are mostly individuals, the receipt of confirmations from each one of them is proving to be almost an impossible task.
VAT invoices must be issued within five days as of the date of the taxable event or the date of receipt of an advance payment. In case of intra-Community supplies of goods (including the cases where an advance payment is made) VAT invoice should be issued by 15th of the month following the month in which the taxable event took place.
The amounts indicated on invoices can be in any currency, provided that the taxable base and the VAT amount are indicated in Bulgarian leva (BGN). Invoices must be prepared in Bulgarian (in practice, invoices could also be drafted as bilingual).
In case of intra-Community supplies of motor vehicles, distance selling of goods and supplies as an intermediary in a triangular transaction, the invoice must include additional requisites. Failure to issue an invoice results in penalties. Electronically submitted invoices could be stored in another Member State of the EU when the taxable person has provided electronic access to the stored documents to the Bulgarian revenue authorities.