How to send an e-invoice to a public sector institution

In short

If you sell a product or service to an Estonian ministry, local government, school or other public sector entity, send it structured e-invoice, not PDF. All public sector entities are registered in the commercial register as recipients of e-invoices, so e-invoices are the only correct format by default, unless you have agreed otherwise. If you do not have your own invoicing software, you can send e-invoices to the public sector completely free of charge through the state's e-invoice provider.

Should I send a PDF or structured e-invoice?

According to § 7¹ of the Accounting Act When selling goods or providing services to a state accounting entity, a local government unit, a legal person under public law, an accounting entity under their dominant influence, or a contracting authority within the meaning of § 5 of the Public Procurement Act, a machine-processable invoice, or e-invoice, must be submitted, with exceptions provided for in the law.. From the summer of 2025, there is a clear logic behind this. According to the Ministry of Finance's explanation replaced the 2019 general public sector e-invoicing obligation with a „buyer chooses“ principle in 2025, which also extended to the private sector. Any accounting entity that has publicly registered itself in the commercial register as an e-invoice recipient can request an e-invoice from the seller.

For public sector entities, this choice has already been made. They are all listed in the commercial register as recipients of e-invoices, which is why the previous e-invoice-first regime essentially continued for them. In practice, this means one thing: when you send an invoice to a ministry or a municipal government, the default format is a structured e-invoice, unless you have agreed in writing on another format.

What is a structured e-invoice? It is an invoice that is already created digitally, in a machine-readable file according to a common standard, and moves directly from the seller's system to the buyer's. The Ministry of Finance emphasizes that An e-invoice is not just an image, such as a PDF, but something more.. It allows for the automatic transfer of data from one system to another without anyone having to manually retype numbers. A PDF can accompany an e-invoice for a person to read the invoice conveniently, but a PDF alone is not an e-invoice.

Step 1: How to identify the right buyer and their receiving channel?

Before you send anything, you need to know who the invoice is actually going to. In public sector institutions, it is easy to get confused between the legal buyer and their subdivision. The invoice should go to the legal entity that is the actual party to the transaction, not to a specific department or school building that does not invoice independently.

According to the definition of the RTK, a public sector unit is a broad concept. This includes the state and state institutions, local government units and their institutions, other legal entities under public law, and all foundations, non-profit associations and companies under their direct or indirect controlling influence.. So a municipal foundation or a state-owned company also counts as a public sector buyer here.

Where can you find the right buyer and their channel? Two places:

• Up-to-date admission information is in the commercial register. RTK refers to the commercial register as a source of up-to-date information on e-invoice recipients, from there you can see whether and through which operator the buyer receives e-invoices.
• List of public sector transaction partners. RTK maintains a list of all public sector entities are listed separately with their registry code and name, and the list is updated monthly. The "RKOARR" page of the same Excel file lists the sub-units that generally do not invoice themselves. This will help you understand whether your contact person represents an independent buyer or not.

When concluding a contract or accepting an order, also ask the buyer for specific references: contract number, order reference, contact person, cost center or other identifier that the institution wants to see on the invoice. There is no law that requires a single nationwide mandatory reference field for every public sector invoice, but each institution has its own internal procedures, and if this reference is missing from the invoice, the payment often stops. It is better to ask for this number right from the start than to correct the invoice later.

Step 2: Create an invoice that the buyer's system can digest

Format. There are two e-invoice standards in use in Estonia: the older Estonian standard and the European standard. The Ministry of Finance recommends the European standard, also known as the Peppol invoice, as its distribution expands across the European Union.. The European standard is based on EN 16931-1. This is a unified e-invoice data model, according to which invoices prepared in Estonia are considered compliant. According to the amendment to the Accounting Act, an e-invoice is presumed to be compliant if it complies with EN 16931-1, although the parties may also agree on another suitable standard.. The safe choice is therefore the EN 16931-1 based Peppol invoice.

Mandatory details. If you are a VAT payer, you must include everything on the invoice that you Section 37(7) of the VAT Act requires:

• invoice serial number and date of issue;
• the seller's name, address and VAT number;
• the name and address of the buyer and his registration number if he has a tax liability for the transaction;
• name and quantity or volume of the goods or services;
• the date of issue of the goods or provision of the service, if it differs from the invoice date;
• price excluding VAT;
• taxable amount by VAT rate, including rates;
• the amount of VAT payable in euros.

Example: You are a small business owner and provided training services to the municipal government for 1,200 euros excluding VAT. Your Peppol invoice would then contain: sales invoice number and date of issue, your company name, address and VAT number, the legal name and registry code of the municipality as the buyer, a description of the service („training 12.08.2026“), the amount of 1,200 €, VAT 24% or 288 € and the amount payable of 1,488 €. Next to that, you put what the municipal accounting department itself asked for, for example the contract number and contact person, because without it the invoice will remain in their house. The payment deadline is indicated as agreed in the contract.

Step 3: How to send the invoice?

Two practical ways, and the choice depends on whether you already have billing software or not.

Through your operator. If your company uses accounting or billing software that is interfaced with an e-invoice operator, you create the invoice there and you send it to your e-invoice operator, who will forward the file to the buyer. You click "Send", and the network of operators delivers the invoice to the buyer's operator. This is the most convenient way if you send invoices to the public sector regularly.

Through the state e-invoice and free of charge. If you do not have billing software or want to send public sector invoices without an operator contract, the state has created an e-biller information system. RIK confirms that Using e-invoice to send invoices to the public sector is free of charge, in unlimited quantities and for an indefinite period, provided that you use it only to prepare and send digital invoices to state authorities and do not make any other transactions. There is also no administration fee when sending e-invoices only. The environment is interfaced with all operators operating in Estonia, so the invoice will arrive regardless of which operator the buyer is a customer of.

Before using the e-invoice, a contract must be concluded. It can be concluded by members of the management boards of private limited companies, public limited companies and other companies, as well as members of the management boards of non-profit associations and foundations, and sole proprietors.. The e-invoice is located in the business portal, you log in with your ID card or Smart-ID.

Step 4: Send, check the route and correct errors properly

Sending does not end with the click of a button. Once the invoice has been sent, check its status in your software or e-invoice to see if the invoice has reached the buyer's operator and whether it was accepted. This is where the idea of a structured e-invoice lies: a network of operators provides feedback that an email never does.

This is also why you shouldn't just send an invoice as a PDF via email. An email goes from one end to the other without any confirmation, the buyer's system doesn't automatically read the data, and if the email gets lost in the mailbox, no one will know. The public sector buyer expects a machine-readable file anyway, so a PDF via email just means someone has to manually type the data again, and the invoice is delayed.

If the route does not work, for example, the invoice does not arrive or is rejected, check three things. Is the buyer's registry code correct and matches the list of transaction partners? Have you sent the invoice to an independently invoicing legal entity, not a subsidiary? And is the receiving channel indicated in the buyer's commercial register still active? Often, the error is in the first or second point.

Correction: If there is an error in the sales invoice you sent, do not quietly overwrite the old invoice or send a „corrected“ version with the same number. The Ministry of Finance considers a credit note to be the correct document for the correction.. The clean path is usually two-part: issue a credit note to cancel the original invoice, and then create a new, correct sales invoice with a new number. This way, the accounting trail remains intact and the buyer side can clearly see what happened.

What changed on July 1, 2025 and what didn't?

The old and new order often get mixed up here, so it's worth untangling the two things.

The old system came into effect in 2019: a general obligation to submit an e-invoice was introduced in Estonia when the buyer was a public sector institution. It was a one-way rule that only affected the public sector.

The new regime came into effect in 2025. The obligation was replaced by the buyer's right to choose the form in which he wants to receive the invoice, and the "buyer chooses" principle was extended to the private sector.. The right to request an e-invoice is now available to everyone who has publicly registered themselves as an e-invoice recipient in the commercial register. Within the meaning of the law, this right is granted by Accounting Act § 7¹ subsection 7. For the public sector, this essentially means a continuation of the old regime, as they are all already registered as recipients. However, unlike before, they now have the right to make exceptions if necessary and also accept invoices in other formats.

Two misconceptions are worth dispelling right away. First: there is no single mandatory national invoice portal in Estonia where all public sector invoices should be uploaded. The invoice moves through a network of operators, and e-invoice is one free path, not the only permitted channel. Second: do not assume that a mandatory national B2B e-invoice mandate has already been approved in Estonia for a specific year. Currently, the buyer choice model applies, and the e-invoice requirement arises when the buyer has registered as a recipient.

Next sign: EU cross-border B2B reporting from 2030

If you look beyond today's municipal government invoice, there is one date worth keeping on your calendar. It concerns cross-border B2B trade, not how you send an invoice to an Estonian public buyer today.

We are talking about ViDA, or the "VAT in the Digital Age" initiative, with which the EU is modernizing the VAT system. According to the European Commission's overview, the ViDA package was officially adopted in March 2025 and will be gradually introduced until 2035.. For an entrepreneur, the most important milestone is in the middle: from 1 July 2030, new Digital Reporting Requirements will apply to cross-border B2B transactions, based on mandatory e-invoicing, and e-invoicing will become the default method of invoicing.

This does not change how Estonian public buyers are billed today. But the direction is clear: the structured e-invoice, which you already have in your hands for the public sector, will become a central tool for cross-border trade by 2030. If you master this model today for local government invoices, you will be ready when the same logic extends to your Latvian or Finnish customer.

The practical conclusion for today remains simple. Check the buyer's registry code and channel, create an EN 16931-1-based Peppol invoice with all the requisites of the VAT Act, send it either through your operator or e-invoice provider, and correct the errors with a credit note. Leave the PDF in the email.

FAQ

Do I have to send an e-invoice to a public sector institution or is a PDF acceptable?

The public sector buyer expects a structured e-invoice, not a PDF. From the summer of 2025, the „buyer chooses“ principle will apply – and all public sector entities are registered in the commercial register as e-invoice recipients, so e-invoice is the only correct format by default.

How to find the correct registry code and receiving channel for the buyer?

The correct buyer is a legal entity, not a subdivision. You can find the acceptance information in the commercial register and in the RTK public sector transaction partners list, which is updated once a month.

What format should an e-invoice be in?

The Ministry of Finance recommends the European standard EN 16931-1 (Peppol invoice). This is a unified data model that ensures invoice compliance and automatic processing.

How to send a public sector e-invoice for free?

If you don't have invoicing software, use the state's e-invoicing service on the business portal. It's free, unlimited, and interfaces with all operators.