From time to time GASPOOL publishes tender invitations for the balancing product Short-Term Balancing Services (STB) at short notice. Once a tendering round is opened, all registered providers may submit bids via GASPOOL’s tendering platform for balancing services. We then accept appropriate bids on a least-cost basis as and when needed by issuing so-called “call orders” to the relevant providers. In their STB bids providers may specify variable call lead times, with bid sizes to be expressed in whole numbers. In deciding which bids to accept GASPOOL will take the specified call lead times and bid sizes into account. Call orders will only be issued for the full bid size, however. A contract for the supply or receipt of the gas quantity offered by the provider is formed once GASPOOL has issued a call order on the provider’s bid.