(a) The trust shall have 15 calendar days after receipt of an invoice at the appropriate designated payment office to notify the contractor of:

(b) The notice of defect shall include the reasons that the trust believes that a defect or impropriety exists.

(c) Whenever a proper notice of defect is given to a contractor, the required payment date shall be 45 calendar days, after any defect or incompleteness in an invoice or voucher or in delivered goods, property or services or any suspected impropriety shall be rectified.

(d) If the trust fails to issue a notice of defect within 15 days of the receipt of invoice, the payment period shall be reduced by the number of days between the 15th day after the receipt of the invoice and the date of notification.

(e) Effective January 1, 1989, the required payment date shall be 30 calendar days, excluding legal holidays, after the correction of any defect or impropriety.