Subcontractor disclosure in federal Swiss tenders: a three-step timeline

Most SMEs that bid on federal Swiss tenders bring at least one subcontractor along: a specialist trade, an integration partner, a translator. The 2021 BöB reform tightened the rules on who must be named, when, and what compliance the main bidder carries for them.

When this post applies, and when it does not.

✅ Applies: federal procurement under BöB (e.g. Bundesverwaltung, federal sectoral buyers, federal sub-units). The articles cited below are from BöB SR 172.056.1.

❌ Does not apply (yet): cantonal procurement under IVöB 2019. Each canton publishes its own rules on Subunternehmer-Ketten, charakteristische Leistung, and disclosure timing. Confirm at the cantonal portal before applying these patterns to a cantonal bid. We will publish a separate cantonal walkthrough once we have audited the five largest cantonal regimes.

The federal rule, in one paragraph

Article 31 BöB, titled “Bietergemeinschaften und Subunternehmerinnen”, sets the framework. Subcontracting is allowed by default, but the buyer can restrict or forbid it in the Pflichtenheft. The charakteristische Leistung (the defining substance of the contract) must “grundsätzlich” be performed by the main bidder, not delegated. Subcontractors that contribute to the work must comply with the same Art. 12 BöB obligations (work protection, equal pay, ILO core conventions, environmental law) that bind the main bidder. The main bidder writes those obligations into the subcontract.

Three articles do the heavy lifting:

• Art. 31 Abs. 1: “Bietergemeinschaften und Subunternehmerinnen sind zugelassen, soweit die Auftraggeberin dies in der Ausschreibung oder in den Ausschreibungsunterlagen nicht ausschliesst oder beschränkt.”
• Art. 31 Abs. 3: “Die charakteristische Leistung ist grundsätzlich von der Anbieterin zu erbringen.”
• Art. 12 Abs. 4: “Die Subunternehmerinnen sind verpflichtet, die Anforderungen nach den Absätzen 1–3 einzuhalten. Diese Verpflichtungen sind in die Vereinbarungen zwischen den Anbieterinnen und den Subunternehmerinnen aufzunehmen.”

The three-step timeline below operationalises those articles.

Step 1: At bid submission

Read the Pflichtenheft first. Art. 31 Abs. 1 BöB lets the buyer restrict or forbid subcontracting. If the Pflichtenheft contains “Subunternehmer sind nicht zugelassen” or “Subunternehmer bedürfen der vorgängigen schriftlichen Zustimmung”, you bid accordingly. If the Pflichtenheft is silent, subcontracting is allowed.

If subcontracting is allowed and you intend to use one:

• Name each subcontractor in the bid, with the legal entity name, the UID, and a one-line description of the scope they will cover.
• Attach each subcontractor’s own Selbstdeklaration. Art. 12 Abs. 4 obliges the main bidder to ensure the subcontractor meets the Art. 12 requirements; the Selbstdeklaration walkthrough is the standard way to evidence this. The subcontractor signs its own form. Do not sign on the subcontractor’s behalf.
• Confirm the charakteristische Leistung remains with you. “Charakteristische Leistung” is not numerically defined in the statute. In practice, it is the part of the contract that gives the work its defining identity: the consulting in a consulting contract, the construction in a construction contract. Delegating it to a subcontractor risks exclusion under Art. 31 Abs. 3.
• Confirm Mehrfachbewerbungen are allowed. Art. 31 Abs. 2 lets a subcontractor appear in multiple bids only if the Pflichtenheft explicitly permits it. If your candidate subcontractor is also bidding directly, check the Pflichtenheft before naming them.

Buyers occasionally ask for the subcontractor’s Eignungsnachweise alongside yours. If the Pflichtenheft requires this, treat the subcontractor’s eligibility evidence as part of your own Eignungsnachweis. A bid that names a subcontractor without the requested evidence fails Eignung as a whole.

Step 2: At contract execution

Once the contract is awarded, you cannot simply swap subcontractors. Art. 31 Abs. 3 obliges the main bidder to perform the charakteristische Leistung; the named subcontractors are part of the legal package the buyer accepted. Changing them requires the buyer’s prior agreement.

What this means operationally:

• Document the work split between you and each subcontractor in writing before contract signing. This is your defence if the buyer later disputes who did what.
• Build the Art. 12 obligations into the subcontract: work-protection law, equal pay, ILO core conventions, environmental law at the place of performance. Art. 12 Abs. 4 requires this in writing.
• If a subcontractor under-performs or a personnel change forces a substitution, notify the buyer in writing and request agreement. Substituting without notice is a contract breach that, under Art. 44 Abs. 1 Bst. h BöB (“mangelhafte Erfüllung früherer Aufträge”), can ground exclusion from future federal tenders for up to five years (Art. 45 Abs. 1).

The post on what the 2021 reform changed covers the broader exclusion framework. The relevant point for subcontracting is that the consequences of getting it wrong outlive a single contract.

Step 3: Sanction and reporting

The main bidder is responsible for its subcontractors’ compliance with Art. 12 BöB. If a subcontractor violates work-protection rules, fails ILO obligations, or runs into environmental-law breaches at the place of performance, the buyer can exclude the main bidder under Art. 44 BöB and revoke the award. Art. 45 Abs. 1 then provides the sanction: exclusion “von künftigen öffentlichen Aufträgen für die Dauer von bis zu fünf Jahren”. The sanction reaches “eine Anbieterin oder Subunternehmerin”: both can be added to the federal exclusion list.

For SMEs, the implication is concrete. Picking a subcontractor that runs a marginal Schwarzarbeit-risk site can lose you federal contracts you have not even bid on yet. Due diligence on subcontractors before naming them is cheaper than five-year exclusion afterwards.

Three things SMEs sometimes get wrong

Treating the charakteristische Leistung as a percentage. Lower-court Praxis has sometimes applied a rule of thumb (often quoted as 50%) but the statute does not give a number. The “charakteristische Leistung” is qualitative: the work’s defining nature, not its share of the BoM. A construction contract whose construction work is fully subcontracted is in trouble under Art. 31 Abs. 3 even if you carried 60% of the budget elsewhere.

Assuming subcontractor Eignung mirrors yours automatically. Art. 27 BöB Eignungskriterien target the Anbieterin. Subcontractors must meet the Art. 26 Teilnahmebedingungen and the Art. 12 obligations; they do not automatically need to meet every Eignung gate the buyer set for you. Unless the Pflichtenheft explicitly requires it, which it sometimes does for the contract-critical portion.

Mixing federal and cantonal rules. This post is federal-only. IVöB 2019 has parallel but not identical rules; cantons additionally regulate Ketten-Subunternehmer (sub-sub-contracting). Confirm the canton’s regime before applying federal patterns to a cantonal bid.

Working with TenderLift

We parse the subcontracting clauses on the federal tenders we ingest and tag whether subcontracting is allowed, restricted, or forbidden. The tag shows up in the tender detail surface, and you can wire it into a saved search that filters out tenders that ban delegation entirely. Useful when you routinely work with one or two specialist subcontractors.

Reminder: cantonal subcontractor rules vary. This walkthrough is federal-only; always confirm at the cantonal portal before applying these patterns to a cantonal bid.

Sources checked

• Federal procurement law. Bundesgesetz über das öffentliche Beschaffungswesen (BöB), SR 172.056.1: Art. 12 Abs. 4 (Subunternehmer-Pflichten), Art. 26 (Teilnahmebedingungen), Art. 27 (Eignungskriterien), Art. 31 (Bietergemeinschaften und Subunternehmerinnen), Art. 44–45 (Ausschluss/Sanktionen).
• Cantonal regimes (out of scope here). IVöB 2019 and individual cantonal procurement laws; each canton’s portal is authoritative for its own subcontractor rules.
• Last reviewed: 28 May 2026.