The bill you already owe
Tax is the only bill that grows silently with every payment you receive. Qoyla reserves its slice the moment money lands, so the figure on the assessment and the figure in your reserve meet as old friends.
An entrepreneur invoices irregularly, some months three payments, some months none. Qoyla reserves the tax slice per payment, not per month, so a quiet month never creates a shortfall and a strong month never feels richer than it is. By filing season the reserve holds the full estimate plus what it earned while waiting.
Set the reserve once; every payment after that files a little of your return.