NAV asks about eVAT: where does the migration stand, and where do you stand?

What does this mean for you?

For companies

For a company, the first question is which channel you will use for the December 2026 or Q4 return. Every other task depends on that decision.

Web interface: NAV compiles a draft return from the data it holds; you check it, amend it where needed and submit it. For simpler, mainly domestic transactions this is usually the fastest route.

XML upload: you upload an eVAT XML generated by your own system. The supplementary sheet data has to be in the XML; it cannot be added on the interface afterwards.

M2M: your ERP or filing software sends the analytics over a machine-to-machine connection. This requires a technical user, interface permissions, tax-code mapping and testing — worth starting in good time. Registration steps

Whichever you choose, make the decision before the December close and test it on an earlier period.

For accounting firms

For an accounting firm, the task is not one return but a whole client portfolio: the first eVAT return of every monthly and quarterly client falls due on the same day, 20 January 2027.

Client portfolio: group your clients by channel. Who can use the web interface, and who needs XML upload or M2M because of volume, source systems or complexity?

Permissions: check them client by client. In eVAT, operational permissions and — for machine submission — interface access are set up separately. If a gap only surfaces in January, the deadline is at risk.

Accounting software: clarify which eVAT version and channel your software supports, and from when. That tells you where you need another solution.

The survey: NAV’s survey is aimed squarely at accountants. If your firm already has eVAT experience, write it down — NAV will use it to decide where to provide support.

How SimplyX handles eVAT M2M

Where do you stand in the eVAT migration?

Choose whether you are answering as a company or as an accounting firm, and mark where you are today. At the end, you get the next steps in order of priority.

1. Have you decided which eVAT channel you will use for the first return?
   • Not yet — Choose the channel first: it determines the registration, permissions and preparation you need. (Route chooser)
   • We have a candidate, not yet final — Record the decision and the reasons behind it — volume, source systems, complexity of transactions. Everything else builds on it.
   • Yes, decided
2. For companies: Do you know which systems the VAT return data comes from?
   • Not mapped yet — List the source systems and who owns each data set. The eVAT analytics are document-level, so every source has to be visible in them.
   • The main sources are known — Add the exceptions: manual corrections, out-of-period items, documents coming from separate systems.
   • We have a full data and ownership map
3. For accounting firms: Have you grouped your clients by channel and complexity?
   • Not yet — Start with high-volume clients, those with foreign transactions or several source systems — they need the most work.
   • Partly — Record the channel, the responsible colleague and the test period for each client.
   • Yes, recorded per client
4. For companies: Have you mapped your ERP VAT codes to the NAV tax codes?
   • Not started — Start with the most frequent transaction types, and flag where one internal VAT code may map to several NAV tax codes. (Standard tax-code catalogue)
   • Done for the common cases — Review the exceptions and test the mapping on real data from a closed period.
   • Done and tested
5. For accounting firms: Do you know what your accounting software supports in eVAT?
   • We don’t know — Ask for a written answer on which eVAT version and channel the software supports, and from when. Without it, January cannot be planned.
   • Partly — Ask about the missing details: supplementary sheets, self-revisions, handling NAV feedback.
   • Yes, in writing
6. For companies: Are your eVAT permissions in place?
   • Not looked at yet — Go through the registration: the technical user, the keys and the eVAT permissions are separate steps on different interfaces. (eVAT M2M registration step by step)
   • In progress — Check every step of the registration, including the keys and interface access. (eVAT M2M registration step by step)
   • Set up and tested
7. For accounting firms: Are permissions in place in eVAT for each client?
   • Not checked yet — Check client by client. If a gap only surfaces in January, it puts the deadline at risk. (eVAT M2M registration step by step)
   • For some clients — List the missing permissions and agree them with the clients concerned in good time.
   • In place for every client
8. Have you tested a submission in the test environment or on a closed period?
   • Not yet — Pick a closed period and run the whole process on it. For XML, validate the file against the schema first. (eVAT XML checker)
   • Partly, with individual cases — Extend the test to the exceptions: self-revisions, corrections, tax codes that require a supplementary sheet.
   • Yes, on a full period
9. Do you know what to do when NAV returns an error or a warning?
   • No process yet — Review which messages the system can return and assign an owner to handle them. (All eVAT validation messages, searchable)
   • Handled case by case — Record who owns which message type and how quickly they have to respond. (All eVAT validation messages, searchable)
   • Owner and process in place
10. Do you know when the return counts as actually submitted?
    • No — Over M2M, once the uploaded analytics have been processed successfully, the return has to be submitted in a separate step. After submission it cannot be withdrawn; corrections are made by self-revision.
    • Roughly — Record in your process who triggers submission, when, and how you check its status afterwards.
    • Yes, it is part of our process
11. For accounting firms: Have you planned for the 20 January peak?
    • Not yet — Schedule the December close so that the first eVAT returns do not pile up in the last few days. Start with the most complex clients.
    • We have a plan, not yet broken down by capacity — Break it down by staff member and week, allowing time for NAV feedback as well.
    • Yes, scheduled

• For companies: Discovery: The first job is a clear picture. Several basic questions are still open. That is no reason for alarm, but the order matters: channel and data sources first, then permissions and testing. The steps below are ordered by your answers. Choose your channel · How eVAT M2M works
• For companies: On track: The foundations are there; the risk is in the details. Most decisions have been made, but some open points would only surface at the live submission around 20 January. A test run on a closed period is the fastest way to bring them to light now. eVAT M2M registration · eVAT XML checker
• For companies: Ready to test: You are in good shape — now for a full test run. The building blocks are in place. Run a complete period from upload to submission, and record who does what when NAV reports an error. That way the January return becomes routine. Request a SimplyX consultation or trial · eVAT validation messages
• For accounting firms: Discovery: First, you need a map of your client portfolio. Many questions are still open at firm level. Grouping your clients brings the most: it shows where the web interface is enough and where more preparation is needed. The steps below are ordered by your answers. Choose your channel · How eVAT M2M works
• For accounting firms: On track: The firm is moving, but the January peak is still a risk. The basic decisions are made, but there are gaps for some clients or steps. On 20 January they would all surface at once, so it is worth closing them now, starting with a test run for one or two clients. eVAT M2M registration · How eVAT M2M works
• For accounting firms: Ready to test: The firm is prepared — now extend it to the whole portfolio. Decisions and permissions are in place. The next step is to run the test for several clients and find out whether your capacity covers the January returns that are all due at the same time. Request a SimplyX consultation or trial · Talk to us