When is an invoice mandatory?

An invoice is mandatory for every supply between VAT-registered persons, for advance payments, for intra-EU supplies, exports and sales to public authorities. For sales to individuals it is mandatory only if the customer requests it (ZDDS Art. 113 §3).

Can an invoice be handwritten?

Yes — the law allows handwritten invoices on paper, provided all 14 fields under ZDDS Art. 114 are filled in legibly. For higher volumes we recommend electronic issuance — faster, error-free and auto-archived.

How long must I keep invoices?

Under Art. 12 of the Accounting Act: primary documents (invoices, cash receipts) — 5 years, accounting registers and annual financial statements — 10 years, and payroll records — 50 years. Electronic archiving is equivalent to paper.

What is the difference between an invoice and a proforma?

An invoice is a tax document that charges VAT and triggers a payment obligation. A proforma is a quote or pre-payment notice — it does not charge VAT and is not entered into the sales ledger. After payment is received, the real invoice is issued.

How do I issue an invoice without VAT registration?

If turnover is below 100,000 BGN (51,130 EUR) over 12 months, registration is not required. You issue invoices without VAT with the wording "supplier is not VAT-registered". Fakturka.bg supports this regime even on the free plan.

Can I invoice a foreign customer?

Yes. To a VAT-registered EU buyer — ICS at 0% VAT (with VIES validation). To a non-EU buyer — export at 0% VAT with customs documentation. To an EU individual — standard 20% or the OSS scheme if you are OSS-registered.

What is reverse charge in ZDDS?

Reverse charge under Art. 82 ZDDS shifts the VAT accounting from supplier to recipient. It applies to certain cross-border services between registered persons in the EU, construction services, and waste supplies. The invoice is marked "reverse charge".

When is an invoice invalid?

An invoice is defective if any of the 14 mandatory fields is missing, the number is duplicated, the VAT regime is wrong, or the recipient's VAT number is invalid. The recipient loses input VAT deduction rights and the supplier faces a penalty.

How much does VAT registration cost?

Mandatory VAT registration with NAP is free. It requires filing a Form Art. 96 ZDDS application within 14 days of crossing the threshold. Registration takes effect on the 14th of the following month. If you use an accountant, they will charge for paperwork (typically 50-200 BGN / 26-102 EUR).

PEPPOL (Pan-European Public Procurement OnLine) is a European network for standardised exchange of electronic invoices in UBL XML format. Since 2019 all EU public authorities have been required to accept invoices through it. Bulgaria has been progressively rolling out PEPPOL for B2G transactions since 2024.

Complete Guide to Invoicing in Bulgaria 2026 — VAT, PEPPOL, FAQ

Complete guide to invoicing in Bulgaria 2026: invoice types, ZDDS Art. 114 requirements, VAT, PEPPOL e-invoicing, FAQ. By Fakturka.bg.