How to prepare for e-invoicing in Slovakia: a step-by-step plan

1 January 2027 is approaching fast. From that date, Slovak VAT payers must issue domestic B2B and B2G invoices as e-invoices over Peppol, and every business must be able to receive them. Here is a practical, step-by-step plan to get your business ready in time.

New to the topic? First read our overview of e-invoicing in Slovakia from 2027 and our article on e-reporting.

Step 1: Determine what applies to you

• Are you registered for VAT in Slovakia? Then you must issue e-invoices for your domestic B2B and B2G supplies.
• Not registered for VAT? You don't need to issue e-invoices, but you must be able to receive them.
• Do you invoice abroad or to consumers? Most cross-border invoices and ordinary B2C invoices are not yet in scope, but check special cases such as chain transactions and fixed establishments.

Step 2: Map your invoice flows

List all types of documents you issue and receive: sales invoices, credit notes, debit notes, advance invoices, self-billing invoices, invoices with reverse charge or VAT exemptions. For each type, note who the customer is (business, government, consumer, foreign) and which software creates the document. This shows you where changes are needed.

Step 3: Choose your e-invoicing solution

You can only send and receive e-invoices through a provider certified by the Financial Administration. You have two options:

• Invoicing software with a built-in Peppol connection, such as onFact: you keep invoicing as usual, and the software takes care of the format, sending, receiving and reporting.
• A separate provider connected to your ERP: more flexible for large companies with complex systems, but it requires integration work.

When choosing, check: is the provider in the Financial Administration's register of certified providers? Are incoming e-invoices delivered directly into your software? How are rejected invoices and errors handled? What does it cost for your volume of invoices?

Step 4: Check your Peppol ID and register

In Slovakia, your Peppol ID is based on your tax identification number (DIČ): 0245: followed by your DIČ. Entities that only have an IČO need to obtain a DIČ to be registered on the network. Your provider registers your Peppol ID so that your suppliers can find you.

Step 5: Clean up your master data

• Collect the DIČ and IČ DPH of all your Slovak customers and suppliers.
• Check the VAT rates and VAT categories of your products and services.
• Make sure exemption reasons and reverse-charge texts are correctly set up.
• Check your own company data: name, address, tax numbers and bank details.

Incorrect master data is the most common reason why e-invoices are rejected.

Step 6: Adapt your processes

• Corrections: never change an issued invoice; use a structured credit or debit note that refers to the original.
• Timing: issue invoices within 15 days.
• Incoming invoices: decide who checks and approves received e-invoices and how they reach your accountant.
• Archiving: keep e-invoices for 10 years in XML, together with the transmission evidence.
• Back-up procedure: agree on what to do if your provider or software is temporarily unavailable.

Step 7: Test before 2027

Voluntary onboarding and testing is possible throughout 2026. Send test invoices to a few customers, receive invoices from suppliers that are already on Peppol and check that credit notes and special VAT cases work correctly. The earlier you start, the more relaxed your go-live will be.

Step 8: Inform your customers and suppliers

Let your customers know you will send e-invoices over Peppol and share your Peppol ID with your suppliers. Ask them for their Peppol IDs and check that they are ready too.

Checklist

• Scope determined (issue and/or receive)
• Invoice flows mapped
• Certified e-invoicing solution chosen
• DIČ and Peppol ID checked and registered
• Master data cleaned up
• Processes for corrections, approval and archiving adapted
• Test invoices sent and received
• Customers and suppliers informed

Get ready with onFact

With onFact you are ready for the Slovak mandate in a few minutes: create your account, enter your company details and DIČ, activate e-invoicing and keep invoicing as usual. onFact sends your invoices over Peppol through our Access Point partner Storecove and receives your suppliers' e-invoices automatically. Questions? Contact us.

This article provides general information and is not tax advice. Rules and deadlines may change; always check the latest publications of the Financial Administration of the Slovak Republic.