Customer number, Easy Switch ID, ICCID: which code?

To switch fixed-line provider, give the Easy Switch ID and the customer number. For a stand-alone mobile line, the deciding code is the SIM card's ICCID, not the customer number. A household that mixes a bundle and several lines therefore has to gather several codes, read in different places.

Which code for which provider switch?

It depends on what you are leaving. The table below gathers what the help pages and guides I read ask for.

Read on 10 October 2026 on the Proximus support page, CallMePower's Easy Switch guide (updated 30 September 2026), the Selectra guide on portability and CallMePower's page on cancelling at Proximus (updated 20 July 2026).

The sources do not agree on everything. Test-Achats, in its 2023 article on the five steps of Easy Switch, only mentions the Easy Switch ID. Proximus demands both. When in doubt, give both.

Where do you find the Easy Switch ID and the customer number?

On the bill, in the online customer area and in the app. Proximus points out that every internet or TV provider must display the Easy Switch ID, and cites MyTelenet, MyOrange and MyVoo as examples of areas where to read it. Orange already wrote it in a press release of 29 June 2017: the identifiers appear on the bill and in the customer area of each fixed operator.

According to CallMePower's guide, the mention sits here:

• at Proximus (own copper, fibre and mobile networks), in the detailed part of the bill and in MyProximus;
• at Telenet (own cable in Flanders and Brussels), on the My Telenet home page, in the order confirmation and at the top of the account statement;
• at Orange (own mobile network, Walloon cable ex-VOO), on the bill, in the customer area and in the My Orange app;
• at Scarlet (Proximus network), on the bill, in the welcome letter and on mon.scarlet;
• at BASE (Telenet group), on the bill, the order confirmation and the customer area;
• at hey! (Orange network), on the bill and in the customer area.

One detail most guides skip: Proximus writes that the identifier is displayed "for each address". It is therefore tied to the home served. A second home or a home office with the same provider will have its own.

Customer number, Easy Switch ID, ICCID, PUK: four codes, four uses

Four numbers look alike and do not do the same job.

• The customer number designates your account with the operator, all services combined.
• The Easy Switch ID belongs to the fixed-line switching procedure, it is tied to an address, and it has carried a check digit since October 2023: the story is in our Easy Switch guide.
• The ICCID is the SIM card's serial number, 19 or 20 digits according to Selectra.
• The PUK unlocks a card locked after wrong PIN codes. It never serves to switch provider, and if you have lost it, the way forward is here.

As for a contract number, none of the pages I read asks for one.

How many codes for a household with four subscriptions?

Five. Take a household that keeps an internet, TV and landline bundle with Proximus, a mobile line with Orange, one with DIGI (own network) and a BASE prepaid card. To leave the bundle, you need the Easy Switch ID and the customer number: two codes, both on the Proximus bill. Each stand-alone mobile line is ported with its ICCID: three more codes, read on three SIM cards.

Result: five codes, four places. The new provider cannot guess them, and reading them in advance avoids interrupting an order halfway. Mobile portability has its own timing: Selectra announces activation within one business day after technical validation, two if the file is complex, with about 30 minutes of downtime and 0 euros for an individual, whereas CallMePower speaks of a same-day transfer. Our guide on switching mobile operator without losing your number details that route.

How do you read a SIM's ICCID?

On an iPhone: Settings, General, About, then scroll. Apple specifies that the ICCID appears with the EID and the IMEI.

What if the bill does not show the identifier?

Look in the customer area first, then act in this order:

1. Open the latest full bill, not the simple payment reminder.
2. Look for the customer area or the operator's app, then the section on switching operator.
3. Call customer service and ask for the Easy Switch ID and the customer number of the address concerned. CallMePower points out that the mention is mandatory.
4. If the operator drags its feet, a report to the Telecommunications Ombudsman Service is free.

There is a precedent. On 22 January 2019, the BIPT (the Belgian telecom regulator, IBPT in French) imposed a 300,000 euro fine on Telenet because the Easy Switch ID did not appear clearly on invoices of business customers on consumer tariffs.

Four mistakes that block a file

• Giving the Easy Switch ID of another address, when it is tied to the home served.
• Retyping the code by hand instead of copying it, when the identifier carries a check digit.
• Mixing up the ICCID with the IMEI, which show on the same iPhone screen.
• Cancelling the old contract before the new one is active: it is the only move that creates a real outage.

Once the codes are in hand, the bundle ranking gives current prices to choose the destination.