Estonia B2B E-Invoicing in 2026: What Does the Buyer’s Choice Model Require?

Estonia does not require every B2B invoice to be electronic. Since July 1, 2025, a registered E-Invoice recipient may require suppliers to send a structured E-Invoice, with EN 16931 applying by default unless another format is agreed.

Estonia’s current B2B E-Invoicing framework is based on buyer choice rather than a universal obligation requiring every business invoice to be issued electronically. The relevant rules have applied since July 1, 2025, so this should not be presented as a new 2026 mandate. Under the Accounting Act, an accounting entity registered as an E-Invoice recipient may require its supplier to submit an E-Invoice for purchased goods or services.

This creates a conditional B2B obligation. A supplier does not have to issue a structured E-Invoice for every domestic B2B transaction simply because both parties are businesses. However, where the buyer is registered as an E-Invoice recipient and requests an E-Invoice, the supplier must comply with the applicable format requirements.

If the parties have not agreed on another format, the European standard EN 16931 serves as the default reference for the E-Invoice. The parties may agree to use another suitable standard or format.

Estonia has also traditionally used its national XML-based E-Invoice format. This can continue to be used where the parties agree. In addition, Peppol BIS Billing 3.0, which is based on EN 16931, supports interoperable exchange of structured invoices both domestically and across borders.

A structured E-Invoice should not be confused with a PDF invoice sent by e-mail. The practical difference is that a structured E-Invoice contains machine-readable data that can be processed automatically by accounting, ERP or E-Invoicing systems, while a PDF generally requires additional processing or manual handling.

Estonia uses a decentralized model. There is no single state platform through which all E-Invoices must be exchanged. Businesses can use private E-Invoicing operators, accounting software, ERP systems and Peppol-based connections.

The e-Business Register is important because it identifies accounting entities registered as E-Invoice recipients. For suppliers, this means that the invoicing process may need to check the customer’s status and determine whether a structured E-Invoice is required.
For retailers, e-commerce businesses and other companies that issue B2B invoices in higher volumes, the requirement is therefore customer-specific. Their systems should be able to distinguish between customers that require structured E-Invoices and those that do not, while also supporting the agreed format and delivery channel.

For ERP and E-Invoicing providers, Estonia should therefore not simply be configured as a country where “all B2B E-Invoices are mandatory.” The correct treatment depends on the recipient’s registered status and the applicable agreement between the parties.

Estonia introduced mandatory B2G E-Invoicing in 2019. Under the current framework, public-sector entities are registered as E-Invoice recipients, which means structured E-Invoicing remains the normal way to invoice Estonian public administrations.

The 2025 reform changed the legal structure by extending the buyer-choice model to private-sector accounting entities as well. In practice, the public sector continues to rely heavily on structured E-Invoicing, while the same legal mechanism can now also create an E-Invoicing obligation in B2B transactions when the buyer is registered and requires it.

Estonia has also considered a broader VAT-related E-Invoicing obligation. The Ministry of Finance proposed removing the EUR 1,000 threshold for detailed invoice reporting and introducing mandatory E-Invoicing for VAT-registered businesses, with 2027 discussed as a possible implementation year.

However, this planned development should not be confused with the rules currently in force. As of September 2026, the applicable B2B framework remains based on buyer choice. There is therefore no general rule requiring every Estonian business to issue all B2B invoices electronically.

Separately, the Estonian Tax and Customs Board is preparing data-based VAT reporting from April 1, 2027. This reporting development is related to the broader digitalization of VAT compliance, but it is not the same as a currently applicable universal B2B E-Invoicing mandate.
The main operational impact is that businesses may need to manage different invoice treatments for different customers. Customer master data, invoicing workflows and ERP integrations should be able to identify whether the recipient is registered for E-Invoices, determine the required format and route the invoice through the appropriate channel.

This is particularly relevant for international retailers and companies operating centralized invoicing systems across several European countries. Estonia’s current model differs from jurisdictions where E-Invoicing is mandatory for virtually all domestic B2B transactions, so country-specific logic remains necessary.

What should affected businesses do?

Businesses issuing B2B invoices in Estonia should verify whether their customers are registered as E-Invoice recipients and confirm the required format and delivery channel. Where no alternative format has been agreed, systems should be capable of supporting EN 16931-compliant E-Invoices.

ERP and E-Invoicing providers should also keep the current buyer-choice requirement separate from future VAT reporting and possible wider E-Invoicing reforms. From a retail compliance perspective, the main implementation issue is not a single nationwide conversion of all invoices into E-Invoices, but the ability to apply the correct treatment per customer and adapt if Estonia later introduces a broader mandate.

The principal legal basis are the Estonian Accounting Act: Accounting Act-Riigi Teataja supported by guidance on invoices and E-Invoices from the Estonian Ministry of Finance, the Estonian Tax and Customs Board: provides technical information on the planned data-based VAT reporting changes from 2027. Source. Source

Mirko Bijeljanin, Junior Legal Consultant at Fiscal Solutions

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