1. To guarantee the faithful performance of its obligations under the PO/Contract, the VENDOR shall post a Performance Security (P.S.) within thirty (30) calendar days from the acceptance of the Purchase Order in the form of surety bond callable on demand, issued by a bonding company accredited by NGCP, in the amount equivalent to thirty percent (30%) of the total contract price. The Performance Security shall cover Advance Payment Security for contracts with Advance Payment.