Knowledge base

How to create an expense from a receipt

Last updated 17/09/2026
Turn a receipt or bill in your Post Box into an expense, with the supplier, date and amounts filled in for you.

An expense is Mighty's record of something the business bought: who from, when, how much, and what kind of cost it was. You can type one in from scratch, but it's quicker to start from the receipt. Mighty reads the receipt in your Post Box and fills in the expense for you to check.

When to create an expense

Create an expense when there is no bank payment to attach the receipt to yet, or when the payment didn't come from the business at all:

  • You paid with your own money, and the business owes you.
  • It's a bill from a supplier that you haven't paid yet, and you want Mighty to show that you owe it.

If the business has already paid by card or from its bank account, it's usually quicker to match the receipt to the bank payment instead.

Company expense or expense claim?

There are two buttons, and the difference is who paid.

ButtonUse it whenWhat Mighty does
Create expenseThe business pays the supplier.Records a bill the business owes, or has paid.
Create expense claim (paid personally), in the row's menuYou, or someone who works for you, paid with your own money.Records the cost and that the business owes that person the money back.

What Mighty fills in

Mighty reads the whole receipt, not only the total. On the new expense you'll find:

  • The supplier. If you've bought from them before, Mighty uses the supplier you already have, even if the receipt writes the name in capital letters or with different spacing. If they're new, Mighty adds them for you.
  • The date on the receipt.
  • Each line, with its description, quantity and price.
  • VAT (the tax that's included in most prices, which VAT-registered businesses can claim back). Mighty works out whether the prices on the receipt already include VAT or have it added at the end.
  • The currency, if the receipt isn't in pounds.
  • The receipt itself, attached to the expense so you never need the paper copy.

What you still need to do

Mighty creates the expense unfinished. It doesn't count in your accounts until you've checked it and saved it.

  • Choose a category. Mighty never guesses this. The category says what kind of cost it was, such as travel, software or office costs, and it decides where the cost shows in your accounts. If something cost a lot and will last for years, like a laptop, see asset or expense.
  • Check the figures against the receipt. Scans are good but not perfect. Faded ink, handwriting and crumpled paper can all cause a wrong number.
  • Select Save when it's right. Mighty asks for a category first if any line doesn't have one.

If Mighty can't read the receipt

Sometimes a receipt is too faded, too blurry, or not really a receipt. Mighty tells you it couldn't scan the details, and the row's status changes to Error.

A Post Box receipt with the Error status and an Add manually button

You haven't lost anything. Select Add manually on that row. Mighty opens a blank expense with the receipt already attached, so you only need to type in the details. You can also try Re-scan receipt from the row's menu before you create the expense, to see what Mighty is able to read.

Receipts that are really your own invoices

If the document is an invoice that you sent to a customer, open the row's menu and select Create invoice. Mighty reads the customer, date and lines and creates a sales invoice instead. Creating a sales invoice explains what to do next.

Common questions

The supplier name is wrong

Change it on the expense before you save it. Pick the right supplier from the list, or add a new one. This happens most with card receipts, where the name printed at the top is the payment company and not the shop.

Where did my receipt go?

Once it becomes an expense, the receipt is Complete and leaves your Outstanding list. Choose Complete in the Status filter to find it. Its View expense button opens the expense it became.

I created the same expense twice

Delete one of them from your expenses list. To avoid it, look for the Duplicate badge in your Post Box before you start. It shows when you've sent the same file more than once.

I've created the expense. What about the bank payment?

When the money leaves your bank, categorise that payment as paying this expense. Mighty then shows the bill as paid. You don't need to match the receipt again, because it's already stored with the expense.

The receipt is in another currency

Mighty reads the currency from the receipt and sets it on the expense. Check the amount against what actually left your bank, because the exchange rate your bank used decides the real cost in pounds.

How to do it in Mighty

Step 1
Select Create expense on the receipt From the menu, choose Post Box. Find the receipt and select Create expense on its row. Use this when the business is paying.
Step 2
If you paid with your own money, use the menu instead Select the three dots at the end of the row, then Create expense claim (paid personally). Mighty records that the business owes you the money back.
Step 3
Wait while Mighty reads the receipt This takes a few seconds. Mighty then opens the new expense with the supplier, date and each line filled in, and the receipt attached.
Step 4
Choose a category and check the figures Pick a category for each line so Mighty knows what kind of cost it is. Check the supplier, date, amounts and VAT against the receipt, and change anything that isn't right.
Step 5
Save the expense Select Save when everything is right. Back in your Post Box, the receipt is now Complete and has a View expense button that opens the expense.
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