When a tax authority mandates e-invoicing: checking your software and your provider
E-invoicing mandates turn invoicing software into regulated infrastructure, often with a month's notice. These are the questions that decide whether your software and your provider are ready on the authority's date or leave you unable to invoice.
Tax authorities announce e-invoicing steps on their own schedule and in their own language, and the median warning in the notices our news desk published in early October 2026 was about a month. This list is for the moment a notice reaches you, and for choosing software before the next one does. The first section works out whether and when you are in scope; the second checks what your software already does; the third covers the accredited provider that many systems require; the fourth covers rejected invoices and corrections; the fifth your records and data; the last makes sure somebody owns the deadline.
Are you in scope, and from when?
Mandates attach to the entity that issues the invoice and to its tax registration, not to where your customers are. Establish this before talking to any vendor.
Which of your legal entities and tax registrations issue invoices in the country, and which system issues them?
Deal-stopperA subsidiary invoicing from a group ERP hosted elsewhere is still subject to the local mandate. Without a list of registrations mapped to systems, a deadline can pass for an entity nobody thought of.
Ask for: A register of every entity and tax registration, with the invoicing system used by each, kept by finance.
Red flags
- Nobody can say which system issues invoices for a given registration
- Invoices for one entity are issued by a reseller or partner on your behalf
What threshold puts you in scope (revenue band, tax type, sector, use of computerised systems), and what is the first date on which you must act?
Deal-stopperMandates are phased by threshold, and the first action is often earlier than the go-live: appointing a provider, applying for a permit, registering or testing. Missing the first step can make the go-live impossible.
Ask for: The authority's own notice, read directly, with the threshold and every date copied into your record together with the notice's URL and publication date.
Red flags
- You learned the date from a vendor email rather than the authority
- The notice gives a go-live date but you have not found the earlier steps
- A threshold looks back over several years and nobody has checked each of them
What does the notice not say yet: a start date, a technical specification, a list of accredited providers?
ImportantMissing pieces are common in the first steps of a new system. You cannot finish the work until they arrive, but you can choose software and providers able to absorb them quickly.
Ask for: A short list of open points per notice, with a named person checking the authority's page weekly until each is closed.
Red flags
- A vendor claims to be accredited where the authority says none has been
- The plan assumes a date the authority has not published
What your software already does
The vendor's answers in writing become the baseline for every later notice.
Which release of the product supports this requirement for your registrations, and since when?
Deal-stopperA release note with a date is evidence; a roadmap slide is an intention. The difference decides whether you test now or wait and hope.
Ask for: The vendor's release notes or documentation page naming the requirement and the country, and the version you run.
Red flags
- Support is promised for a future release with no date
- Support exists only in a newer edition or a paid add-on you do not have
- Your installation is several releases behind the supported one
Can the software produce the structured format and every mandatory field the authority specifies, including credit and debit notes?
Deal-stopperAuthorities validate invoices field by field and often reject the whole document for one missing value. Credit notes, debit notes and advance-receipt invoices are frequently covered too and are the documents most often forgotten.
Ask for: Sample invoices of each document type generated in a test environment and validated against the authority's specification or sandbox.
Red flags
- Only standard invoices have been tested
- Mandatory fields are filled with placeholder values
- Printouts or PDFs are presented as e-invoices
How quickly after the authority publishes a change does the vendor ship it, and what is its record on the last few?
ImportantMandates keep changing after go-live: new waves, new fields, new document types. A vendor's past response times are the best guide to the next one.
Ask for: The dates of the authority's last two or three changes in the country compared with the dates of the vendor's releases that implemented them.
Red flags
- The vendor cannot name its last release for the country
- Updates arrive only once a year regardless of the authority's schedule
The accredited provider
Many systems route invoices through an accredited intermediary. Treat it as a supplier with access to every invoice you issue, not as plumbing.
Is the provider accredited by the authority today, and where is that accreditation published?
Deal-stopperAccreditation is granted and can be withdrawn by the authority. A provider that is not on the authority's own list cannot carry your invoices, whatever its marketing says.
Ask for: The authority's published list of accredited providers, with the provider's entry, checked on the day you contract and again before go-live.
Red flags
- The provider is accredited in another country but not this one
- Accreditation is described as pending with no date
Does the provider integrate with your software out of the box, and what do you pay per invoice, per entity or per year?
ImportantThe cheapest provider can be the most expensive if the integration has to be built. Per-document pricing grows with your volume and should be modelled at your real numbers.
Ask for: A written statement from your software vendor naming the providers it integrates with, and the provider's price list applied to your annual invoice volume.
Red flags
- Integration requires custom development by you
- Pricing changes after an introductory period that ends near the deadline
If the provider loses its accreditation, raises prices or fails, how do you move, and how long does it take?
ImportantYou cannot stop invoicing while you change provider. A tested route out is part of the decision, not an afterthought.
Ask for: Contract terms on notice, data return and transition assistance, and confirmation from your software vendor that it supports at least one alternative provider.
Red flags
- Only one provider works with your software
- The contract has no data-return clause
Rejected invoices and corrections
Real-time systems reject invoices. What happens next decides whether you get paid on time.
When the authority or the provider rejects an invoice, who is told, how quickly, and how is it corrected and re-sent?
Deal-stopperA rejected invoice may not be legally valid, and a customer may refuse to pay it. If rejections land in a log nobody reads, revenue stalls without anyone noticing.
Ask for: A tested rejection in the sandbox, showing the alert, the person who received it and the corrected invoice accepted.
Red flags
- Rejections are visible only in the provider's portal
- Nobody in finance has seen a rejection message
What happens if the authority's platform or the provider is down: is there an offline or deferred mode, and what does the law allow?
ImportantSeveral authorities allow offline invoicing with later transmission and set rules for outages caused by their own systems. Knowing the rule in advance avoids stopping shipments.
Ask for: The authority's rules on offline issuance and the software's documented offline mode, tested once.
Red flags
- The software has no offline mode
- Staff would stop invoicing during an outage because nobody knows the rule
Records and data
E-invoices are tax records with legal retention periods, held partly by third parties.
Where are the transmitted invoices and the authority's responses stored, for how long, and can you retrieve them without the provider?
ImportantRetention periods of six years or more are common. If the only copy of the authority's validation sits with a provider you later leave, an audit can become very difficult.
Ask for: A retention policy naming the storage location and period, and a test export of a month of invoices with their validation responses.
Red flags
- Validation responses are not stored at all
- Exports are only possible on request to the provider
In which countries are your invoice data processed and stored by the software and the provider?
Worth askingInvoices carry customer names, addresses and transaction details. Some countries require local storage or restrict transfers, and your own data-protection obligations still apply.
Ask for: The vendor's and provider's data-location statements and sub-processor lists.
Red flags
- The provider cannot name its hosting locations
- Sub-processors change without notice
Who owns the deadline
E-invoicing sits between finance, IT and procurement, which is how deadlines fall through.
Who is accountable for each country's deadline, and who watches the authority's page between notices?
Deal-stopperA named owner and a weekly check turn a month's notice into a month of work instead of a week of panic.
Ask for: A named owner per country in your compliance calendar, with the authority's page and the next date recorded.
Red flags
- The deadline is owned by 'the vendor'
- Nobody has checked the authority's page since the last go-live
Does the time left before the first action date exceed the time your organisation needs to approve, contract and test a change?
ImportantIf it does not, escalation has to happen now. Internal approval time is the part of the timeline buyers most often forget.
Ask for: The first action date minus your typical approval, contracting and testing time, written down and reviewed by the owner.
Red flags
- The result is negative and nobody has escalated
- Testing time has been assumed to be zero
This checklist is general guidance, not legal, security or financial advice, and it does not replace your own advisers on anything contentious. It was last reviewed on 5 October 2026. Tell us if something here is wrong or missing.