accrual

(countable, uncountable) The act or process of accruing; accumulation.
(countable, uncountable) An increase; something that accumulates, especially an amount of money that periodically accumulates for a specific purpose
(countable, uncountable) from the creditor's viewpoint, a charge incurred in one accounting period that has not been, but is to be, paid by the end of it.
(countable, uncountable) Recruitment (of participants) to a clinical trial.