How Expenddy works
Expenddy turns a list of things people paid for into a single number per person: what you owe, or what you are owed. Here is the whole process, and the arithmetic behind it.
The five steps
Create a group
Start a group for the trip, the flat, the couple or the one-off event, and give it a name. Group types are General, Trip, Home, Couple and Other.
Add the people sharing the cost
Invite members by email, phone number or an invite link. People who are not on Expenddy yet can be invited, and the invitation attaches to their account when they sign up.
Record an expense
Enter the amount and what it was for, choose who paid, pick who shares it, and choose the split method — equal, exact amounts or percentage. Attach a photo of the bill if you want a record of it.
Check the balances
Expenddy recalculates immediately and shows what you owe and what you are owed, per person. There is no mental arithmetic and no spreadsheet to update.
Settle up and record it
Pay whoever you owe in cash or by whatever transfer you normally use, then record the settlement in Expenddy. The balance clears, and the payment stays in the settlement history. If you record it wrongly, you can void or edit it.
The arithmetic, shown in full
Expenddy's balance calculation is deliberately simple, because a number people are asked to trust has to be one they can check. For each person in a group:
A positive balance means they are owed money. A negative balance means they owe. Because every expense adds to both sides of that subtraction, the balances across a group always sum to zero — if they did not, money would have appeared from nowhere.
Worked example: a weekend away for four
Ali, Bea, Chris and Dee share a weekend. Three of them pay for different things, and one expense is not shared by everyone.
| Expense | Amount | Paid by | Shared between | Split |
|---|---|---|---|---|
| Cottage | £400 | Ali | All four | Equal — £100 each |
| Groceries | £120 | Bea | All four | Equal — £30 each |
| Petrol | £60 | Ali | All four | Equal — £15 each |
| Spa session | £90 | Chris | Chris and Dee only | Equal — £45 each |
Result: Ali paid £460 and owes £145, so is owed £315. Bea paid £120 and owes £145, so owes £25. Chris paid £90 and owes £190, so owes £100. Dee paid nothing and owes £190. The four balances (+£315, −£25, −£100, −£190) sum to zero.
Notice what the spa session did: because it was shared between two people rather than four, it never touched Ali's or Bea's balance. Choosing who shares an expense is the single most useful control in the app, and the one most often skipped.
Settling up
At the end of the weekend, three people owe Ali. Each of them pays Ali directly — in cash, by bank transfer, or however they normally pay — and then records the payment in Expenddy. Recording it is a separate action from paying, because Expenddy never moves the money itself.
- Bea pays Ali £25 and records it. Bea's balance goes to zero.
- Chris pays Ali £100 and records it. Chris's balance goes to zero.
- Dee pays Ali £190 and records it. Dee's balance goes to zero, and Ali's £315 clears with the last payment.
That is three transfers in total. Paying each person back bill by bill as it happened would have taken ten — three for the cottage, three for the groceries, three for the petrol and one for the spa. Netting the whole weekend into one number per person is the point. Expenddy keeps a dated settlement history of each transfer.
If you record a settlement wrongly
A settle-up can be voided or edited afterwards, and the balance movement is reversed exactly. The original record is annotated rather than deleted — so the history can still answer both “what was recorded” and “was it later taken back”. This matters months later, when a disputed balance needs explaining and nobody remembers the details.
When you do not need a group
A group is the right shape for three or more people, or for any cost you want a shared record of. Two other shapes exist for cases where a group is overkill:
- Lending one person money. A one-to-one ledgerrecords “you gave” and “you got” entries with a running balance, and needs no group and no splitting.
- Tracking your own spending. Personal recordsare private to you and never appear in anyone else's view.
Questions about the process
How does Expenddy split expenses?
When you add an expense you enter the total, choose who paid it, and select which members share it. You then pick one of three split methods: equal, exact amounts, or percentage. Expenddy turns that into a share for each person, subtracts what they already paid, and updates the balances immediately. Nobody has to do the arithmetic.
Can I record settlements when someone pays me back?
When a payment happens you record it in Expenddy as a settlement, and the balances clear by that amount. Expenddy keeps a dated settlement history of who paid whom. If a settlement was recorded by mistake it can be voided or edited, and the balance movement is reversed exactly — the original entry is annotated rather than deleted, so the history stays accurate.
How do I invite someone who does not use Expenddy yet?
You can invite someone by email address, phone number or an invite link even if they have never used Expenddy. They receive the invitation, and when they sign up it is matched to their new account automatically, so the group and its history are waiting for them.
Does Expenddy actually move the money?
Expenddy does not move, hold or transfer money, and it is not a bank or a payment service. You pay each other however you already do — cash, bank transfer, or any payment app — and then record in Expenddy that the payment happened. Expenddy is the record of who owes what, not the mechanism for paying it.
Try it with one expense
Record a shared expense, see the balance update, and settle it when the money moves.
Free to use. Available for Android and in any web browser. An iOS app is in development and is not released yet.