Payment allocation: one payment, applied fairly
A member pays ₹10,000 against three unpaid bills and some interest. Where that money goes decides their arrears, the interest that keeps accruing and whether they appear on the defaulter list. KeyMatrix applies it by a stated rule, shows the result on every bill, and locks what is settled.
Payment allocation decides which bills a payment settles. KeyMatrix applies each payment to interest first and then to the oldest bill, following the order of appropriation in the Indian Contract Act, unless the payer directs a different split. Part-paid bills show what remains, surplus becomes an advance, and reversals need a recorded reason.
Why the order of a payment matters
Most society payments do not match a single bill. A member three months behind sends a round figure. A tenant pays this month’s bill while last quarter’s is still open. An owner returning from abroad clears everything at once and adds a little extra. In each case somebody has to decide which bills the money settles, and in a spreadsheet that somebody is whoever records the receipt.
The decision is not cosmetic. Interest in most societies runs on the oldest unpaid amount, so a payment applied to the newest bill leaves the expensive debt in place and lets interest keep accruing. A payment applied without a rule produces statements that two people would reconstruct differently, which is exactly what a member disputes and an auditor flags.
Allocation is also where a society’s records first become contestable in law. If a recovery matter ever reaches the registrar or a court, the first question is what was owed and what was paid towards what. A ledger that can show the rule it followed answers that; one that cannot invites the member’s version.
The rule behind the order
The default order is not a software preference. It follows the general law on appropriation of payments, which every society inherits.
Appropriation under the Indian Contract Act, ss. 59–61
Sections 59 to 61 of the Indian Contract Act, 1872 set the order in which a payment against several debts is applied. Under section 59, if the debtor says which debt the payment is for, it goes there. Under section 60, if the debtor says nothing, the creditor may choose. Under section 61, if neither has chosen, the payment discharges the debts in order of time — oldest first.
Courts have generally treated interest as being paid before principal unless the parties agreed otherwise. KeyMatrix uses that as its default: accrued interest first, then the oldest bill, then the next. A society whose bye-laws or general body set a different order should configure that instead; the software applies whichever rule is set, the same way, to every payment.
When the payer directs the split
A member is entitled to say what their payment is for. If they pay ₹4,800 and say it is for the September bill, it goes to September, even though July is older. The office records that direction on the payment, and the allocation follows it instead of the default.
This matters most in disputes. A member who contests a special charge but accepts the maintenance bill can pay the maintenance and leave the contested item open, and the ledger shows exactly that rather than quietly absorbing the payment into the disputed amount.
A ₹10,000 payment against ₹14,820 owed
Flat B-304 owes three months of maintenance and some interest, and pays a round ₹10,000 by UPI. The default rule settles interest and July in full, leaves August ₹20 short, and leaves September untouched.
| Item | Amount due | Applied from ₹10,000 | Left to pay |
|---|---|---|---|
| Interest accrued on overdue bills | ₹420 | ₹420 | ₹0 |
| July maintenance (INV-2627-000214) | ₹4,800 | ₹4,800 | ₹0 |
| August maintenance (INV-2627-000377) | ₹4,800 | ₹4,780 | ₹20 |
| September maintenance (INV-2627-000541) | ₹4,800 | ₹0 | ₹4,800 |
| Total | ₹14,820 | ₹10,000 | ₹4,820 |
Bills that are partly paid, overpaid or reversed
Partially paid bills
A bill that has received some money shows it plainly: amount billed, amount paid, amount left, and the payments that contributed. In the example above, August shows ₹4,780 received against ₹4,800, and the member’s next bill carries the ₹20 forward as an earlier due rather than hiding it inside a new total.
Ageing reports read the same figures, so a part-paid bill ages on its remaining balance and the defaulter list reflects what is actually outstanding.
Advances held against the unit
When a payment exceeds everything owed, the surplus is kept as an advance for the unit, not as a negative balance on a bill. If B-304 had paid ₹15,000, the extra ₹180 would sit as an advance and be applied to the next bill when it is raised. Advances belong to the unit, so they appear on the unit’s financials and survive a change of tenant.
Reversals with a recorded reason
A cheque bounces, a UPI reference turns out to be wrong, a payment was recorded against the wrong flat. The payment is reversed rather than deleted: the reason is recorded, the bills it settled reopen, and the audit trail keeps both the original entry and the reversal. Nothing disappears, which is what lets the treasurer explain a balance six months later.
Interest that stays inside the limit
Interest on late payment is where societies most often overreach. Many bye-laws set a ceiling — the Maharashtra model bye-laws, for example, are commonly cited as allowing simple interest of up to 21% a year on arrears — and some states set a lower figure or a different method. A society charging more than its bye-laws allow is collecting money it may have to refund.
KeyMatrix calculates interest within the limit of your state’s rule pack, adjusted to your own bye-laws, and shows it as its own line rather than folding it into the bill amount. On ₹4,800 overdue for 60 days at 21% simple interest, that line would be about ₹166. Check your bye-laws for the rate and method that apply to you.
Terms on a member’s statement
Five words that come up whenever a member asks why their balance is what it is.
- Allocation
- The record of which bill, or which interest charge, each rupee of a payment settled.
- Appropriation
- The legal term for the same choice. The Indian Contract Act sets who makes it and in what order.
- Advance
- Money received beyond what is owed, held for the unit and applied to its next bill.
- Reversal
- Undoing a recorded payment with a reason, which reopens the bills it settled without deleting the original entry.
- Locked bill
- A fully paid bill. It cannot be edited without first reversing the payments against it.
Paid bills lock, and collectors don’t keep the books
Once a bill is fully paid it locks. Its amount, heads and due date cannot be changed quietly afterwards; a correction means reversing the payments and raising a fresh bill, both of which leave a trail. This closes the oldest form of ledger trouble in societies, where a settled bill is edited and the difference absorbed somewhere nobody looks.
Payments come in through one engine whoever records them. A resident’s UPI claim with its reference, verified by the office; a cheque or NEFT entered by staff; cash taken by a field collector against a monthly target — each is allocated by the same rule and lands in the same ledger. Collectors handle money, and the treasurer reconciles it, so the person who takes cash is never the person who keeps the books.