Winning a public tender is half the job. The other half — where margins are protected or destroyed — is contract execution. For supply and services contracts, Law 4412/2016 prescribes the mechanics of guarantees, delivery, acceptance, penalties and modifications, and it rewards suppliers who manage those mechanics as deliberately as they managed the bid.

The Statutory Skeleton

  • Law 4412/2016 (as amended, principally by Law 4782/2021) governs the execution of public supply and services contracts — guarantees, delivery, acceptance, penalties, payment and modifications.
  • A performance guarantee is required under Article 72 — as a rule calculated on the contract value net of VAT, released only after full and proper performance.
  • Contract modifications are permitted only within the limits of Article 132 (mirroring EU Directive 2014/24), including the de-minimis margin of up to 10% of the value for supplies and services.
  • Delivery and acceptance run through formal committees (επιτροπές παραλαβής); late delivery triggers statutory penalties, and repeated failure can lead to forfeiture of the guarantee and exclusion consequences.
  • Payment follows certified acceptance and complete documentation; the EU late-payment framework (Directive 2011/7/EU) applies to public buyers.

Where Suppliers Win or Lose After the Award

1. The contract you sign is the tender you submitted

In Greek public procurement there is no post-award renegotiation: the contract mirrors the tender documents and the successful offer. Every commitment made to score evaluation points — response times, SLAs, key personnel, delivery schedules — becomes an enforceable obligation. The execution file should begin with a consolidated register of exactly what was promised.

2. Deadlines and extensions are formal, not commercial

Delivery times run from contract signature (or order) and can be extended only through the statutory procedure, on timely request and for justified reasons. Suppliers who continue performing through buyer-caused delays without documenting and formally requesting extensions discover that the statutory penalty regime does not care whose fault the calendar was.

3. Acceptance is a procedure, not a formality

Supplies and services are received by acceptance committees against the contract's technical specifications. Partial rejections, replacement obligations and re-inspection cycles are all regulated. Practical discipline: deliver with complete documentation, insist on timely committee action, and record every interaction — the acceptance file is what a dispute will be judged on.

4. Penalties and the guarantee are the buyer's levers

Late or non-conforming performance triggers statutory penalty deductions and, in serious cases, forfeiture of the performance guarantee and termination with exclusion consequences for future tenders. Because the levers are largely automatic, prevention — realistic scheduling at bid stage and early formal notification of impediments — is worth far more than remediation.

5. Modifications only through Article 132

Quantities, specifications and timelines can change only within Article 132's limits — the de-minimis margin, unforeseeable circumstances, or review clauses drafted into the original documents. Anything beyond is a new award. Suppliers should treat any informal request to "just deliver a bit more / something different" as a compliance risk, not a courtesy.

6. Payment discipline

Payment requires certified acceptance plus complete supporting documentation (invoices, tax and social-security clearances). The late-payment rules give statutory interest against slow buyers — a right suppliers rarely invoke but should preserve through correct invoicing and formal reminders.

Framework Agreements: The Execution Layer Most Bidders Underestimate

A growing share of supply and services spending runs through framework agreements with call-offs (executive contracts). The framework sets the ceiling terms; the call-offs create the actual obligations. Suppliers should track drawdowns, validity periods and mini-competition mechanics as carefully as the original award — frameworks reward organised vendors and quietly punish passive ones.

The Practical Takeaway

Execution risk in supplies and services is procedural: registers of commitments, formal notices, complete acceptance files, disciplined invoicing. In our procurement practice — more than 25 years and €3.5bn+ of tender value — the pattern is constant: the suppliers who treat contract execution as a managed project keep both their margin and their eligibility for the next tender.

Frequently Asked Questions

Can a Greek public supply or services contract be modified after signature?

Only within the limits of Article 132 of Law 4412/2016 — including the de-minimis margin of up to 10% of the contract value for supplies and services, unforeseeable circumstances, or review clauses provided in the original tender documents. Changes outside those limits require a new award procedure.

What happens if delivery under a Greek public contract is late?

Statutory penalties are deducted, and serious or repeated failure can lead to forfeiture of the performance guarantee and termination with exclusion consequences. Extensions are possible only through the formal procedure, on timely and justified request.

When is the performance guarantee released?

After full and proper performance of the contract, following final acceptance — which is why complete, well-documented acceptance files are commercially valuable, not bureaucratic overhead.

Sources & Further Reading

  1. Law 4412/2016, Articles 72 (guarantees), 132 (modifications), 200 et seq. (execution of supplies and services contracts), as amended by Law 4782/2021
  2. Directive 2014/24/EU, Article 72; Directive 2011/7/EU on late payment — EUR-Lex
  3. EADISY — Single Authority for Public Procurement — eadhsy.gr
  4. Promitheus / ESIDIS platform — promitheus.gov.gr

This article provides general information and does not constitute legal advice. Contract-specific terms and the current text of the law always control.