Do I need to provide the buyer with an invoice?
As a rule, in various countries there are laws and regulations requiring the provision of an invoice when goods or services are supplied. If you are not sure about the requirements of your country, we recommend that you contact your local tax authorities for details.
If you are a seller from the European Union, then for more information about the rules for issuing invoices, you can refer to the website of the European Commission — https://taxation-customs.ec.europa.eu/vat-invoicing-rules_en
Do not forget that strict adherence to the rules and requirements is important for successful business and avoiding possible negative consequences.