Your tax authority already has your invoice data — is your VAT return ready for the comparison?

For decades, VAT compliance was retrospective. You kept your records, filed your return at the end of the quarter, and the tax authority trusted your numbers unless something triggered an audit.

E-invoicing changes this fundamentally.

In every country where e-invoicing is mandatory, your tax authority now holds a real-time or near-real-time record of your B2B transactions. Italy's SDI processes every FatturaPA invoice. Poland's KSeF stores every B2B invoice with a unique reference number. Greece's myDATA receives invoice summaries within 24 hours of issue. Spain's AEAT receives VeriFactu data at the point of issuance.

When you file your VAT return, you are no longer reporting into a vacuum. You are submitting a summary that the authority will automatically cross-reference against transaction data it already holds. If those two datasets don't reconcile, you will hear about it.

The authority doesn't wait for an audit to spot a discrepancy. The comparison happens automatically, every period, for every filing business.

This is operational today in Italy, Poland, Spain, and Greece — and it is the explicit design intent of every new mandate being implemented across the EU.

What reconciliation means in practice

VAT reconciliation, in this context, is verifying that the output VAT reported on your VAT return matches the VAT on invoices you submitted to the tax authority's system during the same period:

• The total value of taxable supplies should match your output VAT figures
• Credit notes should reduce the net position consistently across both datasets
• Rejected or cancelled invoices should not appear in your VAT return totals
• The invoice count should be traceable — a complete record of what was submitted, cleared, and included in the return

The tax authority's system does this comparison automatically. The question is whether you have done it yourself before filing.

How it works by country

Italy — SDI and the Agenzia delle Entrate

The Agenzia delle Entrate holds a complete record of every FatturaPA invoice transmitted via SDI. This data is used to pre-populate elements of the VAT return and to cross-check the figures you report.

The Agenzia issues Comunicazioni di anomalia — automated notifications of apparent discrepancies between e-invoice data and VAT returns. The system flags any mismatch between what SDI received from you and what your VAT return reports.

Italy also has the "Liquidazione IVA precompilata" — a pre-filled VAT return generated from SDI data. If your VAT return differs from the pre-filled version, you are required to explain the difference. Unexplained differences lead to enquiries.

Penalties: 90%–180% of the unpaid tax, plus interest.

Poland — KSeF and JPK_VAT

Poland operates the most complete cross-reference system in Europe. Every B2B invoice from February 2026 must be submitted to KSeF and assigned a KSeF number. The VAT return is submitted as the JPK_VAT file — a Standardised Audit File that includes not just summary figures but transaction-level detail.

The KAS (National Revenue Administration) cross-references JPK_VAT line items against KSeF invoice records. The KSeF number must match in both datasets. Any invoice that appears in JPK_VAT without a corresponding KSeF record — or where values differ — is an automatic discrepancy.

Penalties: Up to 100% of the VAT amount on affected invoices, plus potential criminal liability for deliberate misreporting.

Spain — SII and VeriFactu

Spain operates two parallel systems. The SII requires larger businesses to report invoice data to the AEAT within 4 business days of issue. VeriFactu extends real-time reporting to a broader population.

The AEAT cross-references SII-reported data against quarterly VAT returns. Spain's system is notable because it enables triangulation: if your buyer claims input VAT on an invoice that you haven't declared as output VAT, both discrepancies are flagged simultaneously.

Penalties: 15%–20% surcharge if corrected voluntarily; 50%–150% if discovered in an audit, plus interest.

Greece — myDATA

The AADE uses myDATA invoice summaries to pre-populate VAT return fields and identify filing discrepancies. Invoices transmitted to myDATA receive a MARK identifier — the cross-reference point for VAT return reconciliation. Invoices where MARK values differ between the submitted invoice and the VAT return create reconciliation errors. See the Greece myDATA Guide for the full AADE reporting and MARK identifier flow.

The most common reconciliation errors

Most reconciliation mismatches are operational errors, not intentional:

Rejected invoices included in the VAT return. An invoice was submitted and rejected. The rejection wasn't caught, so the invoice remained in the accounting system as "issued" and was included in the VAT return. The authority's records show no corresponding cleared invoice.

Credit notes not linked to original invoices. A credit note reduced the period's output VAT in the accounting system, but was submitted without the correct reference to the original invoice — so the authority's system can't reconcile the two.

Currency conversion differences. An invoice issued in a foreign currency was converted to EUR at a different rate in the e-invoicing system versus the accounting system, creating a small discrepancy that compounds across many invoices.

Period-end timing mismatches. An invoice submitted on the last day of the quarter was processed (cleared) in the next quarter's data. The accounting system included it in the current quarter's return. The two datasets now show different invoice counts for each period.

Multiple channels creating duplicates. Invoices submitted through both an ERP integration and a manual fallback created duplicates in the e-invoicing system. The VAT return includes each invoice once; the authority's data shows two submissions.

Status not tracked for pending invoices. An invoice in PENDING status — waiting for authority clearance — was included in the VAT return on the assumption it would clear. It was subsequently rejected. The VAT return now includes output VAT on an invoice that never received legal clearance.

The pre-filing reconciliation process

Before you file your VAT return for any e-invoicing jurisdiction, you should be able to answer five questions from a single authoritative source:

1. How many invoices did I submit to the tax authority this period, in this country?
2. What is the total output VAT on those invoices — counting only CLEARED or ACCEPTED invoices, not pending or rejected?
3. Are there credit notes that reduce the net VAT position? Are they correctly linked to the original invoices?
4. Are there any invoices in REJECTED status that should not be in my return — and have I resubmitted or cancelled them?
5. Is there any period-end timing discrepancy — invoices submitted near the boundary whose clearance date falls in a different period?

If you cannot answer all five without querying multiple disconnected systems and manually reconciling, you have a reconciliation risk. The manual reconciliation process is also where errors are introduced — a spreadsheet that maps e-invoicing exports to accounting exports is itself a source of discrepancy.

How Clearvo supports VAT reconciliation

Clearvo is designed around the assumption that e-invoice data and VAT return preparation cannot be separate concerns.

Complete status tracking. Every invoice has a clearance status: SUBMITTED, CLEARED, REJECTED, PENDING, CANCELLED. Rejected and pending invoices are never silently included in period totals.

Period-based export. Filter all submissions by submission date, clearance date, country, legal entity, and status. Export as CSV or JSONL from the dashboard or API. The export includes the authority's clearance identifier (SDI receipt, KSeF number, myDATA MARK) alongside Clearvo's internal ID — making cross-reference with your accounting system straightforward.

Credit note linkage. Credit notes submitted through Clearvo carry the reference to the original invoice. The platform flags any credit notes that lack the required cross-reference before submission.

Rejection alerting. Rejected invoices surface immediately via webhook notifications and dashboard alerts. You see the rejection reason, invoice reference, and authority error code in one view — not buried in a log.

Authority identifier capture. For every cleared invoice, Clearvo stores the authority-issued identifier: the SDI Ricevuta di Consegna for Italy, the KSeF number for Poland, the MARK for Greece, the ATCUD for Portugal. These are your proof of compliance and the cross-reference point for VAT return preparation.

Audit trail. Every submission event is logged with a timestamp — submission time, authority response time, clearance time. This resolves period-end boundary questions: if submission was sent 31 March but cleared 2 April, you have the data to make the correct period allocation.

Pre-filing reconciliation checklist

Before filing your VAT return for any e-invoicing jurisdiction:

Export the period's cleared invoices. Filter by country, legal entity, and clearance date (not submission date) for the filing period. This is the dataset the authority is working from.

Verify no rejected invoices are in the period totals. Run a separate query for REJECTED status in the same period. Any rejected invoice that appears in your accounting system as "issued" needs to be reconciled before filing.

Confirm all credit notes are correctly linked. Export credit notes for the period and verify each carries the original invoice reference. Unlinked credit notes may fail authority reconciliation checks.

Check pending invoices from the period boundary. Identify invoices submitted in the last 2–3 days of the period that may still be PENDING. Decide whether to include them in the current period or wait for clearance.

Reconcile total output VAT against your accounting system. The total output VAT on cleared invoices in the Clearvo export should equal the output VAT figure in your accounting system for the same period and entity. Investigate any difference before filing.

Retain the authority identifiers. Store clearance identifiers alongside each invoice record in your ERP. These will be requested if the authority raises a query on your return.

What to do when the authority raises a query

If your tax authority issues a discrepancy notice — a Comunicazione di anomalia in Italy, a JPK query in Poland, or a formal enquiry letter elsewhere — the first thing you need is the supporting evidence:

• Complete list of invoices submitted for the queried period, with submission timestamps and clearance status
• The authority-issued identifiers for each cleared invoice
• VAT calculations per invoice, showing how you arrived at the figures in your return
• Evidence of any credit notes, corrections, or rejections that explain differences

Tax authorities typically require a written response within 30 days (15 days in some Italian cases). Having this evidence immediately available — rather than reconstructing it from disconnected systems — is the difference between a straightforward explanation and a multi-month compliance exercise.

Clearvo's complete audit trail means you can generate the full supporting evidence package from the dashboard in minutes — filtered by period, country, and entity, with every authority identifier and status change logged.

The broader principle

The operational separation between e-invoicing and VAT reporting made sense when the two were truly independent. It no longer does.

In an e-invoicing environment, your VAT return is a summarisation of data the authority already holds at line level. The return is not your primary submission — it's a reconciliation statement against the authority's own ledger. Finance teams that treat e-invoicing as an IT project and VAT compliance as a separate accounting function will routinely face discrepancies between the two.

The finance teams that manage this well are the ones with a single source of truth for all e-invoiced transactions — with clearance status, authority identifiers, and period allocation all tracked in one place — and use that same source of truth as the basis for VAT return preparation.

Clearvo gives your team a single source of truth for every e-invoice — status tracking, period exports, authority identifiers, and rejection alerting across 32 countries from one dashboard.

Related Reading

• KSeF Poland: Complete Guide — the KSeF number and JPK_VAT cross-reference in detail
• Greece myDATA Guide — AADE reporting and the MARK identifier
• Spain VeriFactu Guide — what the new real-time regime means for reconciliation
• EU VAT Reverse Charge Guide — getting the tax code right before it ever reaches reconciliation