Invoice Verification in Procurement Law 2026

Invoice verification in procurement law: formal and substantive review of contractor claims after performance – process, deadlines and legal consequences.

Definition: Invoice verification in the procurement and construction-contract context is the formal and substantive review of an invoice submitted by the contractor by the public contracting authority, which checks whether the services billed were actually performed, the prices correspond to the contractual agreements and the invoice is formally correct.

Last updated: January 2026 · Legal basis: ÖNORM B 2110 Sec. 8, VOB/B § 14 et seq., BGB §§ 641 et seq., Late Payment Directive 2011/7/EU

Significance of Invoice Verification

Invoice verification is an essential instrument of quality and cost control in public procurement and ensures that public funds are spent only on services that have actually been rendered in accordance with the contract. Faulty or negligent invoice verification can result in significant financial losses for the contracting authority and is also relevant under liability law in public administration.

Invoice Verification Process

Invoice verification is divided into a formal and a substantive review.

Formal Review

The formal review examines whether the invoice:

Contains all legally required invoice details (VAT ID, performance date, invoice number, etc.)
Complies with the contractually agreed form (e.g. itemisation according to the bill of quantities)
Was submitted within the agreed deadline

Substantive Review

The substantive review examines:

Were the services billed actually performed?
Do the stated quantities correspond to the quantities actually performed (measurement)?
Do the unit prices applied match the contractual prices?
Are surcharges and deductions correctly calculated?
Are discounts, rebates or contractually agreed deductions taken into account?

Deadlines and Payment Obligations

The Late Payment Directive 2011/7/EU obliges public contracting authorities to verify and pay invoices within 30 days. In Austria, this deadline is implemented by the Late Payment Act (ZVG); in Germany by §§ 286 et seq. BGB and § 16 VOB/B. If the payment deadline is exceeded, the public contracting authority owes default interest.

The 30-day deadline can be extended to 60 days for complex invoices if this is expressly agreed and objectively justified.

Invoice Verification for Lump-Sum Contracts

For lump-sum contracts, invoice verification is simplified, as no measured quantities need to be reviewed. Instead, it is examined whether the agreed service has been fully performed (acceptance certificate) and whether deductions for defects or missing services are justified.

Related Terms

FAQ

May the contracting authority simply reduce an invoice? Yes, insofar as there are substantive reasons (e.g. services not rendered, incorrect prices). The contractor must be informed of the reduction and may assert the difference separately.

What happens if the contracting authority does not verify an invoice on time? Upon expiry of the statutory verification period, the contracting authority falls into default and owes default interest.

Can the contractor sue in case of disputed invoice verification? Yes. After the payment deadline has expired without success, the contractor can assert the outstanding amount in court.

Last updated: January 2026 All information is provided without guarantee. For legally binding advice, please consult a law firm specialising in procurement law.