It is also called  the Offer Kit Warranty, Bid Bond or Tender Bid  or Guarantee for Preliminary Deposit:
And 'the tender guarantee is the obligation that you assume the issuer all'appaltante guarantor to pay a certain amount if the contractor , if awarded, does not fulfill the conditions of the race; that is to sign the contract and release the Good Execution Guarantee (Definitive Guarantee or Performance Bond). In practice, the Bid Bonds (Provisional Guarantees) are issued at the request of a payer contractor (which coincides with the one who presents an offer in the main report) to the guarantor, so that this ensures that all'appaltante:

• the contractor will not withdraw the offer before the auction closes;
• the contractor in case of award-signing the commercial contract;
• the contractor will issue the expected performance bond (Ultimate Warranty).

It 'easy to intuition the usefulness of such a guarantee:
if there is a call for national or international contract, the organizer shall ensure that no advanced questions without serious intentions, but above all that the winner does not withdraw. If the contractor withdrew, indeed, who has called the race would be forced to re-organize the search, taking charge, as well, of further costs, such as updating of the estimates, the additional costs of investigation, the losses due to the possible increase in prices of materials, losses due to possible fluctuations in exchange rates and not least the loss of time. In this perspective, the participation in the tender is typically subject to prior payment of a security deposit or, in lieu, the issue of a surety in favor of the contracting authority. Even in the unlikely event that the race contractor withdrew finding the cheapest deal or because in the meantime failed, or for another reason still, the organizer will collect the sum provided in the cross examination of the Offer Kit Warranty title compensation. Provisional Guarantee usually accompanies the offer documents. The duration of this type of collateral is usually short, from three to six months, in order to allow time for the customer to consider the submitted bids. This surety is commonly required when the contracting is a public body.