# How to keep an IMEI register for a mobile shop

> How a phone shop keeps a record of each phone it buys and sells: the IMEI, the cost, the condition, the warranty and the sale. Plus the weak points of paper.

Source: https://sellypos.com/blog/how-to-keep-an-imei-register-for-a-mobile-shop/
Updated: 2026-11-03

An IMEI register for a mobile shop is a record of every phone you buy and sell, kept by its own code. This guide is for a shop that takes in used phones and sells them on. It is not about tracing a phone that was lost or stolen.

## What a register must hold

For each phone, the record needs these facts:

- **The code.** The IMEI, or the serial number. Some phones have two IMEI numbers, so keep both.
- **Where it came from.** The supplier, or the customer who sold it to you, and the date.
- **The cost.** What you paid for this phone, not the average for the model.
- **The condition.** New, used or refurbished, and any faults you found.
- **The checks.** Whether the phone is locked to a carrier, and whether its locks were removed.
- **The warranty.** What it covers, and until when.
- **Where it is now.** In stock, waiting for a check, with a supplier, sold or written off.
- **The sale.** The date, the receipt number, the customer and the price.

## Where a paper book or spreadsheet goes wrong

A paper book or a spreadsheet can hold all of these facts. Its weak points are the same every time.

- **Typing errors.** One wrong digit in an IMEI makes the record useless when the phone comes back.
- **The same phone twice.** A phone that returns in part payment is written again as a new line, and the first line stays.
- **No link to the sale.** The book says a phone was sold, but not on which receipt. You cannot check the price or the warranty from it.
- **Cost and sale kept apart.** The cost is in one book and the sale in another, so nobody sees what was earned on that phone.
- **Easy to change after the fact.** A line can be rubbed out or retyped, and nobody can tell that it was changed.

## Checks you can make by hand

If you keep a book, these habits keep it honest.

1. When a phone arrives, read its code twice, and compare the two readings.
2. Before you write a code, search the book for it. If it is already there, the phone is not new.
3. When you sell a phone, write the receipt number beside its code.
4. Count the phones on the shelf against the book from time to time.

These habits help, but they depend on a person doing each step every time.

## Where SellyPOS stands

Device tracking is in Professional only. Lite and Basic do not record phones by their codes. In Professional, the register is kept by the software:

- **Each device has its own code.** A phone is recorded by its serial number and one or two IMEIs. One code belongs to one device, so the same IMEI cannot be a second phone.
- **A code already in stock is flagged.** It is shown as a conflict beside the line, not written a second time. A device that has left and comes back shows its history first.
- **Each device is costed at its own cost.** A phone bought back is sold at what was paid for it, not at the product's average.
- **Each device keeps its condition and checks.** The record holds its condition, its battery, a faults and repairs note, and whether it is carrier locked and whether its locks are cleared.
- **The Devices list shows the state.** Each device is In stock, To check, With supplier, Sold or Written off. You can filter by state, or scan a code to open its page.
- **The history stays.** A device's page lists each time it was in the shop. A past event is never edited.
- **Sell by scanning the code.** Scan the IMEI or serial number, and the phone goes into the cart at its own price. The receipt prints its codes and warranty.
- **Warranty for each device.** A cover is for new devices, used devices or every device. A sold phone keeps its own warranty end date.
- **Returns by code.** A return asks for one of the codes the phone was sold under. A different phone is refused.
- **Trade-in.** A customer's old phone can be part of the payment. See [trade-in old phones](/features/trade-in-old-phones/) and [how to take a trade-in](/help/selling/take-a-trade-in/).

The full feature list is on [mobile shop software with IMEI tracking](/features/mobile-shop-pos-imei-tracking/).

## Next

See [how a sale is completed](/help/selling/complete-a-sale/). Then [download SellyPOS](/download/) or [compare prices and editions](/pricing/).