What is a tender guarantee?

A tender guarantee backs a bid with a third party's promise to pay. The bidder's bank or surety undertakes to pay the buyer a set sum if the bidder withdraws its offer before the contract is in place, and the buyer collects by demanding payment from that guarantor. In public and private tendering, the same instrument is also called a bid bond, bid security, or tender bond, and each tender's documents determine which terms apply. Its reach ends at the bid stage. It runs from submission until the contract is signed or the procedure ends, and once a contract exists, other instruments secure what the supplier owes.

How a tender guarantee works

Three parties take part in each tender guarantee: the bidder applies for it, a bank or surety issues it as guarantor, and the buyer holds it as beneficiary. The guarantor pays on a demand that complies with the guarantee's terms, independently of the bid itself.

Bidder, guarantor and buyer

The bidder is the applicant. It is the party whose bid is secured, and it arranges for the guarantee to be issued in the buyer's favour. The guarantor undertakes to pay. The buyer, as beneficiary, is the party that can call it.

In its usual bank form, the instrument is a demand guarantee. The ICC Academy's guide to URDG 758, the International Chamber of Commerce's uniform rules for demand guarantees, describes one as an irrevocable undertaking by a guarantor, usually a bank, to pay the beneficiary when it presents a complying demand. These rules govern a guarantee issued subject to them. A surety's bond can secure the same obligations, but the tender documents decide whether a bond is acceptable at all.

Paid on demand, independent of the bid

Independence is what makes the instrument useful to the buyer. Under the ICC rules, the guarantor must honour a complying presentation independently of the underlying contract, which, for a tender guarantee, means the bid and the tender terms. The guarantor's question is whether the demand matches the guarantee's wording, not whether the bidder in fact withdrew or refused to sign.

That moves where a disputed call is fought. A bidder who thinks a demand is unjustified can't stop the payment by pointing the bank to the bid or the tender documents. The argument is with the buyer. And where the guarantee is issued subject to URDG 758, the bidder cannot instruct its bank to cancel or change it unilaterally once it has been issued.

What the tender documents set

The tender documents set a tender guarantee's amount, form, validity and delivery, and the bidder's bank works to them rather than to its own terms. The European Commission's Instructions to Tenderers for a 2025 supply tender for IT equipment under EU external action (reference EC/BiH/TEN/25/011) show how precise these terms can be. They are one tender's documents, not law, and another buyer's invitation to tender can set each point differently.

Amount

In that tender, the amount is a fixed sum in euros for each lot: €7,000 for Lot 1, €4,000 for Lot 2 and €2,500 for Lot 3. The bidder doesn't calculate it as a share of its price. It reads the figure for the lot it bids for.

A fixed sum also stays put while the bid changes. A bidder that lowers its Lot 1 price during preparation still provides €7,000 in that tender, because the figure is the buyer's and is not tied to the offer's value.

Form and issuer

The guarantee has to be presented in the form specified in the annex to the tender dossier. That annexed form is the buyer's text, so the guarantor issues on the buyer's wording, not on its own standard guarantee.

Who may issue it is a matter for the same documents. Where they name a type of issuer or set conditions for one, the bidder's choice of guarantor is limited to what they allow. A text in any form other than the annexed one doesn't meet the requirement, however sound the issuer.

Validity period

Bidders in the Commission tender are bound by their bids for 90 days from the submission deadline, the period its documents call tender validity. The tender guarantee must remain valid for 45 days beyond that period, so it runs for 135 days from the deadline.

The margin means the guarantee outlasts the bid it secures. Any change to the bid's validity reaches the guarantee too, which is why the documents tie the two together when validity is extended.

Delivery of the signed original

The original signed tender guarantee has to be sent or delivered by hand to the contracting authority. It is a physical document with its own route, separate from whatever goes in with the bid by other means.

At the opening session, the authority may announce whether the requisite tender guarantee is present, where one is required. A missing required document is an irregularity that may lead to the bid's rejection, so an absent guarantee can cost a bid at opening.

How a bid team obtains a tender guarantee

A bid team obtains a tender guarantee by asking the bidder's own bank, or another issuer the tender documents accept, to issue it on the buyer's form, then checking the issued wording against the documents. It is one step in running a tender response, and one that depends on the bank's timing as well as the team's.

Request to the bidder's bank

The applicant asks its own bank to issue the guarantee. Here, the request includes what the documents specify: the amount for the lot, the annexed form, the validity period counted from the submission deadline, and the buyer as beneficiary.

The bank's part comes before the bid goes in. Where the documents require the signed original to be sent or delivered by hand, as the Commission tender does, the time the bank takes to issue and the time the original takes to arrive both sit inside the bid timetable.

Checking the issued wording

The ICC Academy describes the beneficiary reviewing an issued guarantee against the underlying contract on four points: the expiry date, the amount, the documents required with a demand and the form of demand. Where the text doesn't match, the differences go back to the applicant, and the guarantee can be amended.

Here the reference point is the tender documents and their annexed form rather than a signed contract. The same four points apply, and any difference is corrected by amending the guarantee.

When a tender guarantee is called, extended or released

A tender guarantee is called when the bidder fails to meet the obligations its bid carries, extended when the buyer extends bid validity and the bidder agrees, and released at contract signature or at the end of the procedure, on terms each tender sets in its own documents. The Commission tender shows each step from submission to award.

What triggers a call

The Commission's documents word the trigger broadly: the guarantee will be called if the bidder does not fulfil all obligations stated in its bid. Withdrawing the bid between the submission deadline and the end of its validity may result in forfeiture of the guarantee.

Award brings a second trigger. If the winner doesn't sign and return the contract, and any required financial guarantee, within 30 days of notification, the contracting authority may treat its acceptance of the bid as cancelled while retaining its right to seize the guarantee. Because the main trigger refers to every obligation in the bid, the bid and the guarantee's wording together set the bidder's exposure.

When the buyer extends bid validity

A bidder that agrees to extend its bid's validity is bound to extend its tender guarantee for the revised period. A bidder that refuses keeps its guarantee, without forfeiture, but its participation in the procedure ends.

Where the guarantee is issued subject to the ICC rules, the buyer has a second route. Under the extend-or-pay mechanism, a beneficiary can request an extension of the guarantee's expiry instead of immediate payment, so a buyer with a guarantee about to lapse can ask for it to run on.

Release for the winner and other bidders

The winner's tender guarantee is released on signing of the contract, once the performance guarantee has been submitted. In effect, the security of the bid stage hands over to the security of the contract stage.

Release for the other bidders is worded less consistently, even within one document. Section 21 of the Commission's instructions releases unsuccessful bidders' guarantees once the contract is signed, while section 23 says once the procedure is complete. Each tender's documents determine release, and a conflict like this remains open until the buyer clarifies it.

How a tender guarantee differs from other guarantees

A tender guarantee secures the bid up to contract signature. A performance guarantee secures the supplier's performance of the contract after award, and an advance payment guarantee secures repayment of an advance the buyer pays under the contract.

Tender guarantee and performance guarantee

A performance guarantee gives the buyer a sum it can call if the supplier fails to perform the contract as agreed. It belongs to the contract, not the bid. In the Commission's template, it is set at 10% of the contract amount and handed in with the countersigned contract.

The two differ in what sets their size and what they secure. The Commission tender fixes its tender guarantee as a sum per lot, while the performance guarantee follows the contract's value. They meet at signature, where the performance guarantee's arrival releases the winner's tender guarantee.

Tender guarantee and advance payment guarantee

An advance payment guarantee secures the buyer's right to recover an advance it pays the supplier, where the contract provides for one. Like the performance guarantee, it comes after award, and it is tied to money the buyer has already paid out.

A tender guarantee involves no payment from the buyer. It secures the bidder's conduct during the procedure, between the submission deadline and signature.