Business-to-government (B2G) e-invoicing is mandatory in Turkey. All suppliers issuing invoices to public sector entities must do so via the Gelir İdaresi Başkanlığı (GİB) portal, in UBL‑TR 1.2 XML format. E-invoices must be digitally signed and transmitted for validation before delivery to the government. 

Business-to-business (B2B) e-invoicing is mandatory in Turkey for businesses with an annual turnover exceeding TRY 3 million. These businesses must issue all invoices via e‑Fatura. There are also sector-based thresholds in Turkey: ecommerce, real estate, and construction companies, and professional intermediaries must also comply with the mandate if their annual turnover exceeds TRY 500,000. 

Business-to-consumer (B2C) e-invoicing is mandatory in Turkey under certain conditions, using the e-Arşiv Fatura system — part of the broader digital invoicing framework overseen by the GİB. Businesses must use e‑Arşiv Fatura if:

• They are already registered in e‑Fatura
• The invoice is issued to a consumer or unregistered buyer
• The invoice value exceeds TRY 5,000, or the buyer is a taxable person but the invoice exceeds TRY 2,000

If below these thresholds, traditional (paper) invoices may be used for B2C transactions.

E-invoices issued via e‑Arşiv Fatura must be in UBL-TR 1.2 XML format and include a digital signature and QR code. Submission must be reported to GİB within 24 hours of issuance. Both the issuer and the recipient must also digitally archive the invoice for 10 years. 

1. Registration: Businesses must register on the GİB platform using the business’s VKN (10‑digit tax identification).
   
2. Digital certification: Businesses require a digital certificate and fiscal seal; individuals use a qualified electronic signature (QES). 
   
3. Invoice creation format: All e‑invoices must follow the UBL‑TR 1.2 standard format in XML. 
   
4. Transmission path: Via the GİB platform or the e-Arşiv Fatura system.
   
5. Archiving: Invoices must be stored digitally by both issuer and recipient for 10 years. 

Failure to issue or receive e-invoices properly is considered a special irregularity in Turkey. Penalties include a fine of 10% of the invoice value or missing amount, plus a minimum tax penalty of TRY 2,200. Both issuer and recipient can be held liable if they fail to issue or receive invoices in the correct format or timeframe.