o2: Find out customer number - how it works

If you contact the o2 support, you will often need your customer number. We show you how to find out in our practical tip.

Find out the customer number of o2

Your o2 customer number is a ten-digit number that exactly identifies your contract with the mobile operator. You will find the number on each of your o2 bills. Depending on the contract, you can access them in other ways.

• Mobile phone contract: If you have a mobile phone contract with o2, open this website in your browser and log in to your o2 account. Then click on "Download invoice", you will find your customer number at the top of the PDF document.
• My Handy: You will receive your o2 My Handy bill in printed form when you purchase a device. You will then find your customer number on the first page under the barcode.