Before you start

Passport or eID for SIM registration
A Belgian address for fixed broadband
A Belgian bank account for direct debit on most postpaid plans
An unlocked or eSIM-capable handset

Step-by-step

1
Buy a prepaid SIM on arrival and register it
Sold in supermarkets and phone shops and usable immediately, but identification is legally required and an unregistered card is deactivated. You can register with a passport before you have an eID, so this is not blocked by the commune queue.
In personWho: YouDay 1
2
Compare the resellers before signing with the big operators
Mobile Vikings, hey!, Scarlet and others run on the major Belgian networks at much lower prices. Coverage is identical because the towers are the same. The flagship bundles earn their premium mainly when you want mobile and fixed together.
OnlineWho: You
3
Use the BIPT comparison tool
The federal regulator publishes an independent comparison of mobile and fixed offers. It is the only neutral one — commercial comparison sites take commission — and it exists precisely because Belgian bundle pricing is deliberately hard to read.
OnlineWho: You
4
Find out what the building is physically connected to
Wallonia's cable footprint was built by VOO and has since changed ownership, which means brand names and offers have moved around while the physical network under the street has not. Proximus copper and an expanding fibre rollout run alongside it. Ask the landlord what is installed and whether there is a live termination point in the flat, rather than trusting a listing that says 'internet available'.
OnlineWho: You
5
Switch operators with Easy Switch
Belgium's Easy Switch process makes the incoming operator handle the migration and keeps your number with no gap in service. Cancelling the old contract first is the standard mistake and leaves you offline for a week.
OnlineWho: You
6
Book the installation slot early
Fixed-line activation runs one to three weeks out and often needs someone at home. If you work remotely, arrange a mobile data fallback for the first month rather than assuming the line will be live on move-in day.
OnlineWho: You1–3 weeks

Documents you’ll need

Passport or eID for SIM registration
Proof of address for fixed-line installation
Belgian bank account details for direct debit
Landlord permission where cabling work is needed

Things most newcomers don’t know

Anonymous prepaid SIMs were abolished in 2017 and an unregistered card stops working.

Belgian law requires every prepaid card to be tied to an identified holder. You can register with a passport before you have an eID, so this does not block you on arrival — but skipping it does. People who buy a SIM for a partner or a visiting relative and never register it lose both the number and the credit, with no retrospective reactivation.

Source: BIPT

You can walk away from a Belgian telecom contract after six months, penalty-free.

Consumer rules let residential customers end mobile and internet contracts at any point once six months have elapsed, with no early-termination charge. That changes the calculus entirely at signing: there is little reason to trade a long commitment for a discount, and trying an operator carries almost no risk. Providers do not volunteer this, and most customers stay put assuming they are locked in.

Source: BIPT

Wallonia's cable network has a different history from Flanders', and the brand names have moved.

The cable that reaches most Walloon homes was built and run separately from the Flemish network and has since changed hands, so offers, brands and bundles have been reshuffled while the physical infrastructure has not. Practically, this means advice from a Flemish colleague about which provider to choose does not transfer, older reviews describe products that no longer exist under that name, and the only question that reliably answers itself is what is physically terminated in the flat.

Source: BIPT; community-reported

Cable upload speeds are far below the advertised download, which matters if you work remotely.

Cable advertises a large download figure and a much smaller upload one, and the upload is what carries video calls, cloud backups and large file transfers. In Liège, where a meaningful share of higher-paid remote work is for employers in Brussels, Luxembourg or Germany rather than in the city, that is the number to ask about. Fibre where it has arrived solves it; cable does not.

Source: community-reported; BIPT

Common mistakes to avoid

Buying a prepaid SIM and never completing the mandatory registration.
Signing a flagship bundle without checking the resellers on the same network.
Cancelling the old contract yourself instead of using Easy Switch, and losing the number.
Taking a Flemish colleague's provider recommendation at face value in Wallonia.
Assuming symmetric speeds on a cable connection.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.