Introduction Rule One: the 30 day rule
18.Subsection 464C(1) applies where a close company has amounts outstanding (either a loan or advance, or the conferral of a benefit, which gives rise to a charge under sections 455 or 464A CTA10) and during any period of 30 days it:
	receives repayments which:repay a payment chargeable under sections 455 or 464A CTA2010;have not been matched with a chargeable payment under s464C previously; andtotal at least £5,000; andmakes new chargeable payments (which have not previously been matched with a repayment under section 464C):in an accounting period which is later than the accounting period in which the original chargeable payment was made;to the same person or their associate.
19.For subsection 464C(1) to apply, the repayments and new chargeable payments may be in the same accounting period, but the new chargeable payments must be made in a later accounting period than the original chargeable payments.
20.In these circumstances the repayments are treated as repayments of the new chargeable payments so far as the amount of the repayment does not exceed the amount of the new chargeable payment. Repayments are then available to set off against the original chargeable payments only to the extent the repayments are in excess of the new chargeable payments.
21.Subsection 464C(2) determines which new chargeable payments should be taken into account when considering the 30 day period – new chargeable payments which are repaid within the 30 day period under consideration are not taken into account.