The glossary to understand and take action

Sales invoice

A sales invoice describes the transaction invoiced to a customer, with the applicable information and VAT treatment.

Notion comptable, fiscale ou juridique · Luxembourg Fiduciaries Editorial Team · Reviewed on

Understand the scope

Definition and points to distinguish

The invoice date, the performance period and collection are distinct. A credit note must remain linked to the invoice it corrects to ensure accounting and commercial tracking.

In your file

What this changes in practice

The sales invoice must correspond to the transaction actually carried out and to the appropriate tax treatment. Numbering, mandatory information and dates contribute to traceability. Its monitoring continues after issue: sending it to the customer, due date, payment, any dispute and credit note. Revenue recognition also depends on the performance of the service or delivery; it does not always result from collection alone.

A scenario to help you understand

Educational example

A company receives a deposit before carrying out an assignment. It distinguishes the deposit document, the VAT treatment to be reviewed and revenue recognition, then reconciles the final invoice with the amount already paid.

Fictitious situation, presented to illustrate the concept.

Prepare for what comes next

Points to check

  • Qualifier la vente et le traitement TVA
  • Assurer la continuité des références
  • Suivre échéances, avoirs et encaissements

The practical question

Find out more

Faut-il supprimer une facture quand le client demande une correction ?

Une facture déjà émise doit rester traçable. La méthode de correction dépend de l’erreur et du cadre applicable, notamment par un avoir lorsque celui-ci est approprié. Conservez les références entre les documents et vérifiez l’effet sur les déclarations. Modifier seulement le fichier envoyé au client peut rendre incohérents la comptabilité et les justificatifs conservés.

Connecting concepts

Terms to know as well

Continue with the concepts, contacts and procedures related to this topic.

VATValue added tax (VAT) is a consumption tax applied to transactions falling within its scope according to their own rules.Credit noteA document that reduces or cancels all or part of an invoice by identifying the transaction and the correction.Aged trial balanceA statement that allocates receivables or payables by age at a given date, in order to organise their monitoring.ConsumerA consumer is a natural person acting for purposes outside their professional activity, within the applicable definition.PeppolNetwork enabling the exchange of structured documents, including electronic invoices, between participants.VAT numberThe VAT number identifies a person for their value added tax obligations within the relevant system.

Put it into practice

Explore further with our guides

Practical guideVAT in Luxembourg: rates and checks before invoicingPractical guideUnpaid invoices: use an aged receivables report and organise follow-upsPractical guideInvoicing in Luxembourg: the details to checkPractical guideCredit note and corrective invoice: correct without losing the audit trail

Sources and verification

References consulted on 20 September 2026. Official procedures specify the applicable conditions and exceptions.

This guide explains a general process. The applicable rules depend on your situation; it does not constitute personalised advice. Report a correction.

A definition gives you a reference point. To examine your situation, clarify your question with a professional.