b) paying the main contractor an amount that the principal is liable to pay the main contractor for work done under the building contract, excluding payment for subcontracting works12; c) returning an amount paid in error by the principal13; d) transferring an amount to another trust account as required under Chapter 2 of the BIF Act14; or e) making another payment prescribed by the regulation15 . Before withdrawal from the general trust account to pay itself or to make another payment prescribed by the regulation, the main contractor shall ensure that there are sufficient amounts to pay all subcontractor beneficiaries16 after the withdrawal. If there is insufficient amount available in the general trust account to pay the amount to the subcontractor beneficiary, the main contractor shall deposit in to the general trust account the shortfall to make up the sufficient amount17. 2) A retention account holds retention amounts for a subcontract with a subcontractor beneficiary. The main contractor shall ensure that a retention amount for a subcontract with a subcontractor beneficiary is held in a retention trust account18 and shall not withdraw from the trust account unless the payment is made to the subcontractor beneficiary of the amount withheld under the subcontract, or to correct defects in the building work or secure of the subcontract19. 3) A disputed funds account holds amounts the subject of payment disputes at the time prescribed under the BIF Act20. A payment dispute occurs under two situations: (a) a subcontractor beneficiary gives the main contractor a payment claim for a progress payment under s.75 of the BIF Act, the main contractor gives to the subcontractor beneficiary a payment schedule for the progress payment, the main contractor prepares a payment instruction to pay an amount from a trust account to the subcontractor beneficiary for the progress