Bank guarantee: unconditional pay-on-demand obligation secures PSIA recognition and remains continuing and non-revocable. The bank must provide an unconditional and irrevocable guarantee to pay the Government on demand for losses caused by a PSIA's breach of the Handbook of Procedures or other law; the obligation is absolute, payable without demur irrespective of disputes, continues for the period of recognition and performance, is non revocable without Government consent, and permits Government variation of PSIA duties, subject to claims being made in writing within the prescribed claim period.