eVAT M2M: What to Fix Before Migration
eVAT M2M migration is not only XML development. Companies must prepare VAT data, tax codes, controls, deductible VAT logic, and manual processes.
Many companies first approach eVAT M2M migration as a technical project: generate XML, build an interface, set up a submission workflow. That is understandable, but it is too narrow.
The deeper question is whether the underlying data, tax codes, deductibility rules, and internal controls that feed the VAT return are already fit for machine-to-machine filing.
Based on NAV communication around the phaseout of ÁNYK and the arrival of eVAT M2M 2.0, Hungarian VAT reporting is moving away from a form-filling mindset and toward a structured, validated data process.
eVAT M2M does not start with XML
XML is the end of the process. VAT return data is created much earlier: in invoicing, accounting, ERP tax codes, partner master data, Online Számla reporting, and the logic used to determine deductible VAT.
If those points are not governed, M2M submission will not solve the issue. It will make issues more visible: missing fields, inconsistent tax codes, undocumented corrections, or uncertain deductibility decisions.
The main question in 2026 is therefore not whether a technical filing channel exists. It is whether the company can produce VAT analytics that are accurate, traceable, auditable, and suitable for eVAT M2M.
Why an Excel-heavy process becomes risky
In many organizations, VAT return preparation still relies heavily on Excel. Data exported from ERP or accounting systems is cleaned, enriched, reclassified, and reconciled manually by finance, accounting, or tax teams.
Excel is not the problem. It remains useful for checks, reconciliations, and analysis. The risk starts when it becomes the central location of actual filing logic rather than a supporting tool.
This becomes especially problematic when:
the same manual fixes are repeated every month;
filing logic lives in formulas, copy-paste routines, and individual worksteps;
it is unclear which transactions make up a given return line;
the process depends on personal knowledge held by key individuals;
errors are discovered only shortly before the filing deadline;
there is no documented decision process for handling discrepancies.
In an eVAT M2M environment, the company needs more than a completed return. It needs a repeatable data process that can reliably produce and explain the return.
What does clean VAT analytics mean?
Clean VAT analytics is not simply a spreadsheet or an export file. It is a structured record where relevant filing data is assembled according to clear logic and decisions can be traced.
In a well-designed VAT analytics process, it is clear:
which data comes from which system;
which tax code drove the VAT treatment of each item;
how output VAT and deductible input VAT are calculated;
where manual corrections were made and why;
who approved the discrepancy or adjustment;
how a reported figure can be traced back to the original invoice or accounting entry.
This transparency matters because eVAT M2M is not merely a submission channel. VAT reporting becomes a data-quality, control, and auditability question.
M-sheet changes point in the same direction
Preparation for 2026 is not only about the phaseout of ÁNYK and eVAT M2M. Domestic summary reporting, often referred to as the M-sheet, is also moving toward more detailed data requirements.
According to the NAV 2665 completion guide, fields for actually deducted VAT, broken down by VAT rate, are currently voluntary. For the July VAT period — filed in August — they will already be mandatory for ÁNYK-based returns. From a preparation perspective, this means companies need to manage actually deducted VAT data in more detail and closer to invoice level.
This is especially important where the VAT shown on the invoice and the VAT actually deducted are not the same — for example partial deductibility, apportionment, company-car related costs, or other purchases subject to deductibility restrictions.
Where should preparation start?
Before selecting the developer or tool that will generate XML, companies should understand how the VAT return is currently created and which logic is used to produce it.
1. Review source data
Map the systems that feed the VAT return: ERP, invoicing, accounting, AP/AR modules, import and customs data, and any manual registers that affect the VAT position. The goal is to understand where each data point originates, where it changes, and when it enters the filing process.
2. Review tax codes
Tax codes determine the VAT treatment of transactions, how they appear in analytics, and which return lines they affect. Before eVAT M2M, review domestic transactions, reverse charge, intra-EU transactions, export, import, advances, credit notes, partial deductibility, and special exemption grounds. We cover this in more detail in our article on eVAT M2M 2.0 timely preparation.
3. Control Online Számla data
Online Számla reporting is no longer only a technical obligation. Companies should verify whether the data sent to NAV is consistent with invoicing, accounting, and VAT analytics. Discrepancies should be identified before the VAT return is prepared.
4. Govern deductible VAT
Partial deductibility, apportionment, deduction bans, and special cost categories require professional decisions and documented rules. For eVAT M2M, these decisions should not exist only as manual Excel corrections.
5. Define error handling and approval
Automation does not mean there will be no errors. It means errors should become visible earlier. A good process clarifies who reviews warnings, what counts as a technical issue, what requires a tax decision, who approves corrections, and how the decision is documented.
In-house development or an external filing platform?
For eVAT M2M implementation, companies must decide whether to rely on in-house development, ERP-side changes, an external filing platform, or a combination of these.
In-house development can be realistic if the organization has sufficient ERP, integration, tax, and operations expertise, and is ready to continuously follow NAV specifications, validation logic, and changes.
A specialized external filing platform is worth considering when a company wants to manage the full eVAT M2M process — not just XML generation — as a controlled workflow. Such platforms typically cover NAV specification and validation rule tracking, tax-code mapping support, data checks and error handling, submission status monitoring, approval steps, and often multi-company or accounting-firm operation, without maintaining all of that through in-house development, ERP changes, and ongoing operational responsibility.
How SimplyX can help
SimplyX treats eVAT M2M migration as more than an XML generation task. The goal is to support the full VAT return process around structured, controlled, NAV-compatible data.
The platform is designed for companies that need to produce VAT analytics and filing data from verifiable source data, with controls around status, validation, and multi-company operation.
This matters especially where current VAT preparation involves high document volumes, several tax codes, multiple entities, complex ERP environments, or significant manual preparation.
Conclusion
eVAT M2M migration does not start with XML. It starts with the source data behind the VAT return. Technical connectivity is necessary, but not sufficient.
Successful migration depends on how well the company understands its data sources, how consistent its tax coding is, how controlled deductible VAT treatment is, and how clearly error handling is documented.
In 2026, the companies that gain an advantage will not be the ones that replace the current filing process at the last minute. They will be the ones that clean up the data and controls on which eVAT M2M will rely. We also cover NAV M2M and ÁNYK phase-out preparation in a separate article.
Frequently asked questions
What is eVAT M2M?
eVAT M2M is a machine-to-machine connection where a company system or an external filing platform sends structured data to NAV’s eVAT system. Its purpose is not only digital submission, but a more controlled and auditable VAT return process.
Why is XML development not enough?
XML is the end of the process. If source data, tax codes, deductibility logic, and approval points are not governed properly, technical submission alone will not create a reliable eVAT M2M operation.
Can Excel still be used with eVAT M2M?
Yes. Excel can remain useful for checks, reconciliations, and analysis. The risk starts when the actual filing logic, monthly corrections, and decision rules live in spreadsheets, formulas, or personal knowledge held by key individuals.
Where should eVAT M2M preparation start?
Start by mapping the current VAT return process: where data comes from, which tax codes are used, where manual corrections happen, how exceptions are handled, and whether each return line can be traced back to the original invoice or accounting entry.
Who should consider an external filing platform?
Companies with high document volumes, multiple entities, multiple ERP systems, complex tax coding, or significant manual VAT preparation should consider it when they want the full eVAT M2M process — not just XML submission — to run as a controlled, scalable workflow, without carrying in-house development and operations for NAV specification tracking, validation, tax-code mapping, error handling, and status monitoring.