Variant bid (Alternative proposal)

A variant bid (or alternative proposal) is a tender submission that deviates from the base requirements by offering a different way to meet the procurement’s underlying objectives. These bids present innovative or alternative technical approaches while still satisfying the essential performance or output goals of the tender. When allowed, bidders may submit both a compliant base bid and a variant bid to provide contracting authorities with greater choice.

European procurement regulations explicitly permit variant bids—provided doing so is stated in the contract notice or tender documents. Authorities must define the minimum requirements for variants and ensure that the selected award criteria apply equally to both compliant and variant bids. Variant bids must be linked to the contract’s subject matter and cannot be rejected solely because they lead to a different type of contract (e.g., supply vs service). This enables structured flexibility without compromising fairness or comparability.

Allowing variant bids gives buyers flexibility to consider creative solutions, potentially enhancing value for money or introducing novel service delivery methods. However, it also increases evaluative complexity and legal risk. Variant bids should only be submitted when explicitly permitted, and suppliers must ensure their proposals clearly explain deviations and convincingly demonstrate equivalence or improvement over the base requirements.