[Glossary](https://pecuvo.eu/en/glossary/) · Business and projects # Invoice **In short:** An invoice is a document proving the sale of goods or a service — what, when, between whom and at what price — showing VAT separately when the seller is VAT-registered. **Simply put:** For the customer, an invoice proves the purchase — you need it for a complaint, a guarantee or a report. For the business, it is an accounting document. A VAT-registered business sees the tax as a separate line and may use it under the rules. In publicly funded projects every cost must be backed by a document. **Example:** A firm buys a laptop. The invoice shows a base of €1,000, VAT at 20% — €200, total €1,200. The invoice and the guarantee card are kept together. **Watch out:** the compulsory details of an invoice and the deadlines for issuing it are set in tax law — check them with the tax authority, don't write them from memory (*) . A missing document in a project leads to a financial correction. > **Example: Bulgaria** — The standard VAT rate is 20% (VAT Act, Article 66). Not every business is VAT-registered — only those above the legal threshold (€51,130 annual turnover from 1 January 2026, Article 96(1)) or those that register voluntarily. > > **Check in your country** — The EU sets common VAT rules (VAT Directive 2006/112/EC); the details of invoices and thresholds are applied nationally. Ask your tax authority. **Source:** Council Directive 2006/112/EC — https://eur-lex.europa.eu/eli/dir/2006/112/oj · NRA, "VAT in Bulgaria" — https://nra.bg/wps/portal/nra/taxes/dds-v-balgariya (in Bulgarian) ## In depth in the modules - [Module 9](https://pecuvo.eu/en/modules/managing-cash-flow/) - [Module 27](https://pecuvo.eu/en/modules/taxes-and-public-spending/) - [Module 11](https://pecuvo.eu/en/modules/flow-5-projects-and-public-funds/) ## Related terms - [VAT (value added tax)](https://pecuvo.eu/en/glossary/vat/) - [VAT registration](https://pecuvo.eu/en/glossary/vat-registration/) - [Bookkeeping and accounting](https://pecuvo.eu/en/glossary/bookkeeping/) - [Eligible costs](https://pecuvo.eu/en/glossary/eligible-costs/) - [Returning goods (14 days online)](https://pecuvo.eu/en/glossary/returning-goods/)