Installment selling usually starts flexibly , every customer gets the arrangement that suits them. It works at ten agreements. At two hundred, nobody can remember which customer is on which terms, and the reminders start going out wrong.

Standardising early is what lets the programme grow.

Define a small set of standard plans

Three or four named plans cover almost every customer you will meet.
For example: Weekly over eight weeks, bi-weekly over three months, monthly over six months. Name them, publish them, and let the exception be genuinely exceptional rather than routine.

Standardise the deposit too

The deposit should follow the plan, not the negotiation.

• Consistent: Customers compare notes; a deposit that varies without reason reads as arbitrary.

• Risk-based: Vary it by trust score rather than by how the conversation went. That is defensible, explicable, and gets better over time as the score improves.

Write the exception rule down

There will be cases that need something custom, and that is fine. Decide in advance who may approve one, what the limits are, and where the reason gets recorded. An exception someone can explain six months later is a business decision. One nobody can explain is how a portfolio quietly stops being manageable.

Review the mix quarterly

Look at volume and on-time rate for each standard plan.

• Retire any plan that consistently underperforms the others.

• Add a new standard plan only when the exceptions clearly cluster around one shape.

• A tight set of plans that you administer well will always outperform a generous set that you administer badly.