Core concepts

Collector's billing model is built from a handful of concepts that fit together. Once you know these, every screen in the app makes sense.

Product ──(payment rule: amount + frequency)──▶ Obligation (what a member owes)
   ▲                                                 ▲
   │ Enrollment                                      │ Allocation
   │                                                 │
Member ───────────────── Payment (money received) ───┘

Member

A person belonging to your organization. Members have a human-friendly member number, contact details (phone for SMS, email for email — either or both), a status (active / inactive), and a join date. Everything else in the system hangs off the member: enrollments, obligations, payments, and statements.

Product

A thing members pay for — Monthly Dues, Welfare, Building Fund, Harvest Levy. Each product is either:

• Mandatory — Collector generates obligations for enrolled members and tracks arrears when they go unpaid.
• Optional — no obligations are generated; members contribute ad hoc and the payments are simply recorded against the product.

A product can be set to auto-enroll, which enrolls every current member and every future member automatically at registration.

Payment rule

How much a product costs and how often — e.g. GHS 20, monthly, effective from 1 Jan 2026. Frequencies are monthly, quarterly, annually, and one-time.

Rules are effective-dated and historical: to change an amount you don't edit the old rule, you add a new one starting from a date. Past obligations keep the amount that applied when they were created, so your history never rewrites itself. See Products & payment rules.

Enrollment

The link between a member and a product they participate in. Auto-enroll products create enrollments automatically; for other products you enroll members by hand. A newly enrolled member immediately receives the current period's obligation — they don't wait for the next cycle.

Obligation

An expected payment: member X owes amount Y for product Z for period P (e.g. Monthly Dues, June 2026). Obligations are generated automatically — at each period rollover for everyone enrolled, and immediately on registration or enrollment for newcomers.

An obligation moves through statuses:

Status	Meaning
Pending	Generated, nothing paid yet
Partially paid	Some money allocated, not enough to fulfil
Fulfilled	Fully paid
Overdue	Still unfulfilled after the due date plus your grace period

Payment

Money actually received from a member — the amount, the date, and the method (cash, bank transfer, mobile money, or Paystack for online payments). A payment is not tied to a specific month when it's recorded; the allocation engine decides where it goes.

Allocation & credit

When a payment lands, Collector spreads it across the member's outstanding obligations oldest first, filling each one before moving to the next:

• A partial payment moves the oldest obligation toward fulfilled.
• An exact payment fulfils it.
• An overpayment fulfils everything outstanding and parks the remainder as member credit, which is automatically consumed by the member's next obligation — no action needed from you.

This is why members and treasurers never argue about "which month" a payment was for: money always settles the oldest debt first, and anything extra waits as credit.

Receipts, statements, and the audit trail

Every successful payment produces a numbered PDF receipt (emailed to the member when SMTP is configured). Every member has a statement of account showing their obligations, payments, and balance. And every payment and configuration change records who did it and when — a full audit trail for accountability.