Knowledge base

How to send receipts and bills to your Post Box

Last updated 17/09/2026
Email, WhatsApp or upload your paperwork, and Mighty reads it and keeps it ready for you to deal with.

Your Post Box is where your receipts and bills arrive in Mighty. You send them in, Mighty reads them, and they wait in a list until you decide what each one is. It means you can deal with paperwork the moment you get it, and throw the paper away.

This guide covers getting receipts in. When you're ready to deal with them, see matching a receipt to a bank transaction and creating an expense from a receipt.

The Post Box screen, with your Post Box email address at the top and your receipts listed below

Three ways to send a receipt

Email it

Every company in Mighty has its own Post Box email address. It's a long address made of letters and numbers, so don't try to type it. Use the copy button next to it, and save it as a contact.

Forward any email that has a receipt or bill attached. Each attachment becomes its own row in your Post Box. If the email has no attachment, because the receipt is written in the email itself, Mighty turns the email into a PDF and uses that.

Send a photo by WhatsApp

First add your mobile number in Company settings. Mighty only accepts WhatsApp receipts from that number, which is how it knows they belong to your company. Then send a photo of the receipt to the Mighty WhatsApp number shown at the top of your Post Box.

WhatsApp works for photos only. If your receipt is a PDF, email it or upload it instead.

Upload it

Select Upload receipts to add files from your computer. You can upload up to 10 files at a time, and each file can be up to 50MB. Mighty accepts PDFs, photos (JPG, PNG and the HEIC photos that iPhones take), and Word and Excel files.

Photos and PDFs work best. Mighty can store a Word or Excel file, but it usually can't read the details from one.

What happens after a receipt arrives

Mighty scans each new receipt to read 3 things: who the supplier is, the date on the receipt, and the amount. The scan runs about every 15 minutes, so a new receipt shows Scanning for a short while. You don't need to wait for it. You can open and use a receipt straight away.

The scan also hides things that are not receipts, such as the logo in someone's email signature. How Mighty reads your receipts explains how that works and how to get one back.

Mighty never deals with a receipt for you. Nothing is matched to your bank, and no expense is created, until you choose to do it.

Match to bank or create an expense?

Each receipt needs one decision from you. This table shows which button to use.

What happenedWhat to do
The business paid, by card or from the business bank accountMatch to bank. The receipt is attached to that payment as your proof.
You paid with your own money and the business owes youOpen the row's menu and select Create expense claim (paid personally).
It's a bill from a supplier that you haven't paid yetCreate expense, so Mighty knows you owe it.
It's an invoice that you sent to a customerOpen the row's menu and select Create invoice.
It's not a business cost at allOpen the row's menu and select Mark as not an expense, or Delete.

What the statuses mean

The Status filter above the list chooses which receipts you see.

The Post Box with the Status filter set to Complete, showing a finished receipt
StatusWhat it means
OutstandingEverything you still need to deal with. This is what you see when you open the Post Box.
PendingReceived, and waiting for you to match it or create an expense.
CompleteDealt with. The row has a button that takes you to the expense, invoice or bank payment it became.
ErrorMighty couldn't read the receipt when you tried to create an expense. Select Add manually to fill in the details yourself.
AllEvery receipt, including complete ones.
Hidden by MightyImages the scan decided were not receipts, such as email signature logos.

Common questions

Why does a receipt say Duplicate?

Mighty has received exactly the same file twice. That often happens when a supplier emails a receipt and you also upload it. Select the eye button to compare the two, then delete the copy you don't need. The badge is only a warning. Mighty doesn't stop you using either one.

An image from my email is missing. Where did it go?

If it was a logo or a signature image, the scan has probably hidden it. Choose Hidden by Mighty in the Status filter to see what was hidden, and select Restore on anything you need back.

My receipt hasn't appeared

Select the refresh button next to the Status filter. Emails usually arrive within a few minutes. If it still isn't there, check you sent it to the full Post Box address, and for WhatsApp, that you sent it from the mobile number in your Company settings.

How do I tidy up the list?

Open the menu at the end of a row to Rename a file, Mark as not an expense, or Delete it. To change several at once, tick the boxes on the left and use the buttons that appear above the list.

How to do it in Mighty

Step 1
Copy your Post Box email address From the menu, choose Post Box. Select the copy button next to your Post Box email address at the top of the screen. Save it as a contact in your email so it's always to hand.
Step 2
Forward a receipt to that address Open the email that has your receipt or bill attached and forward it to your Post Box address. You don't need to write anything in the email. A few minutes later, select the refresh button on the Post Box screen and the receipt appears in the list.
Step 3
Or select Upload receipts If the receipt is a file or photo on your computer, select Upload receipts at the top right.
Step 4
Choose your files and select Upload Drop your files onto the box, or select it to pick them. You can add up to 10 files at a time. Then select Upload.
Step 5
Wait for the scan A new receipt shows Scanning in the Supplier column while Mighty reads it. When the scan finishes, the supplier, the date on the receipt and the amount fill in.
Step 6
Open the receipt to check it Select the eye button on a row to see the receipt next to what Mighty read from it. From here you can match it to a bank payment or create an expense.
A mobile version of this screen is available. Switch
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