If there was a discrepancy between the contract documents, the contractor would usually inform the Contract Administrator of this before proceeding. The Contract Administrator would then need to investigate the reason behind the discrepancy and identify which one is the correct one before replying to the Contractor.

If an order has already been placed and it’s the wrong quantity, an instruction would need to be produced by the Contract Administrator for an amendment to the Contract so that less/more is ordered and/or returned.

In principle, if the discrepancy is relevant to quantities then the Bill of Quantities takes precedence and if it’s a quality discrepancy then the Specification takes precedence.