A residual commission is a recurring payment to the person who signed a customer, earned every month for as long as that customer keeps buying. Payment processing, merchant services and insurance run on it: the agent's share is recalculated from the customer's actual activity each month, so the amount moves without anyone selling anything.
$95 a month is not a number anyone gets excited about. Twenty-four months of it from a single signature, with no second sale, no renewal call and no upsell, is $2,280. Forty merchants of that size pay the agent $3,800 every month whether or not they get out of bed. That gap between how trivial a residual looks on one line of a statement and how much it is worth in aggregate is the reason experienced agents in payments will take a residual deal over a larger one-time commission almost every time.
The mechanics differ from ordinary commission in one important way: nothing triggers the payment. A closed deal pays once because it closed. A residual pays because a merchant took $42,000 in card payments last month, and it will pay a different amount next month because they took a different amount. The agent's income is therefore a derivative of somebody else's trading, arriving through a processor file that lands late and occasionally changes shape. Insurance works the same way with renewal premium in place of processing volume.
What this changes for the person being paid is where the risk sits. A quota-carrying rep's bad month is a bad month. A residual agent's bad month is attrition, and attrition compounds in the wrong direction forever. An agent who boarded eight merchants and lost eleven had a worse month than the statement shows, because a statement reports what was earned rather than what was lost, and the lost accounts take their whole remaining lifetime with them.
A coffee shop boarded once and never touched again. After the office retention and the agent's split, their share of that merchant's monthly margin settles at $95. No upsell, no second location, no new account.
A straight line overstates any single account, because volume drifts and some merchants close. It understates a book that is still boarding, because every new merchant stacks a fresh line on top of the ones already paying. Real residual income is the sum of two curves moving against each other, which is why forecasting it from last month's total rarely works.
Every agent agreement states the split. Very few state what happens to the book when the agent stops selling, resigns, retires or dies. The possible answers are all in use somewhere: residuals vest permanently, residuals continue at a reduced rate for a fixed term, residuals stop on the last day of employment, or the portfolio is bought out at a multiple of monthly income. An agent who has built six years of income on a document that is silent here owns much less than they think, and the conversation that settles it should happen before the first merchant boards.
The long form lives in the guides: ISO residual commissions.
Commish pays residual commission the way your plan describes it, shows the arithmetic on every line, and traces each payment back to the deal that earned it.