What to Do When You Receive a Late Invoice in Luxembourg

You receive a supplier invoice after your VAT return — or even your income tax return — is already filed. What do you do? Include it in the next period? File a correction? The answer depends on which tax and when the invoice arrives.

VAT: late purchase invoice

The rule

Under the Luxembourg VAT law, input VAT (TVA déductible) should be declared on the VAT return for the period when the VAT became chargeable — not when you received or paid the invoice. In practice, this means the period when the supply was made or the invoice was issued. The guides on what an invoice must show and on correcting one are gathered under invoices and e-invoicing in Luxembourg.

Exception: if you are on the “actual receipts” scheme (regime de la comptabilite de caisse — turnover under 500,000 EUR), VAT deduction applies only when the invoice is paid. In that case, the late invoice issue is less relevant. The same holds when your supplier uses that scheme — its invoice then says « Comptabilité de caisse »: you deduct its VAT only when, and as far as, you have paid (article 48 §2).

What to do — by scenario

Scenario 1: VAT period is still open (not yet filed)
Simply include the invoice in your current VAT return. No correction needed.

Scenario 2: VAT return already filed, but still within the same year
You can claim the input VAT on a later VAT return within the same year, or in the annual return, which restates the whole year (article 64 §7 of the VAT law). For example, if you filed Q1 and the invoice relates to Q1 but arrives in Q2, you can include the deduction in your Q2 return.

Scenario 3: VAT return filed, previous year
If that year’s annual return is not filed yet, include the deduction there — it restates the whole year. Otherwise, file a corrective VAT return (declaration rectificative) through the eCDF system. Under Article 82 of the same VAT law, you have 5 years from 31 December of the year the VAT relates to, to claim it back.

How to file the correction:

1. Log into eCDF (via MyGuichet.lu or eTVA)
2. Go to Submitted returns
3. Use the Copy function on the original return
4. Add the missing input VAT
5. Submit the corrected return — it replaces the original

Do not just skip a late invoice. Unclaimed input VAT is money you’re leaving on the table. You have 5 years to claim it — use them.

Quarterly filers: a common question

If you file VAT quarterly and an invoice for Q1 arrives after you’ve filed Q1:

• If Q2 is not yet filed — you can include the deduction in your Q2 return (same year)
• If the year has ended — include it in the annual return if that is not filed yet; otherwise file a corrective return via eCDF
• Do not ignore it — the deduction is your right, and AED expects correct reporting

Practical tip: Keep a “late invoices” folder. Every time a supplier invoice arrives late, file it there and note which VAT period it relates to. At the end of each quarter, check the folder before submitting your return.

Income tax: late expense invoice

The rule

Under the Luxembourg income tax law (LIR), expenses are deductible in the year they were incurred — not the year the invoice was received. If you received a service in November 2025 but the invoice arrives in February 2026, the expense belongs in your 2025 tax return. That holds on an accrual basis. Under the simplified cash method (recettes et dépenses), an expense counts in the year you pay it, as the ACD’s circular L.I.R. n° 18/5 states — a November 2025 service paid in February 2026 then goes in your 2026 return.

What to do — by scenario

Scenario 1: Tax year not yet filed (Form 100, the déclaration d’impôt)
Include the expense normally in your return. No issue — this is the simplest case.

Scenario 2: Form 100 filed, but tax assessment not yet received
You can send a written correction request to your competent tax office (Administration des Contributions Directes / ACD). Since no tax assessment (bulletin d’imposition) has been issued yet, the ACD can take your correction into account when processing your return.

Scenario 3: Tax assessment already received
Once you receive your tax assessment, you have 3 months from the date of notification of the assessment to file a formal objection (réclamation), as Guichet.lu on contesting an ACD decision states. This is a legally binding deadline — after it passes, the assessment becomes final and corrections are much harder.

The 3-month period runs from when you receive the tax assessment, not from when you filed your return. There can be months between filing your return and receiving the assessment.

The 3-month deadline starts when you receive your tax assessment (bulletin d’impot), NOT when you file your return. If you discover a missed expense, file your objection immediately — don’t wait.

Guichet.lu, “Contester une decision de l’ACD”: “La reclamation doit etre faite dans un delai de 3 mois a partir du jour de la notification du bulletin d’impot.”

Quick reference: what to do when

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