A voluntary agreement may cover a particular task or apply to successive agreements between you and the employee. You or the Contractor may terminate a voluntary agreement at any time by written notice to the other. To determine the amount to be withheld, subtract the Goods and Services Tax (GST) levied in the voluntary agreement from the amount of the invoice to be paid and multiply the result by the withholding tax rate indicated in the voluntary agreement. If the beneficiary`s CIR is not known at the time of the agreement, the 20% flat rate applies. If an electronic agreement is used (e.g. B an email), you must have appropriate IT controls in place to ensure the security and accuracy of the agreement. .