Before you start

National register number, issued after the wijkagent check
Belgian eID, or Bijlage 15 plus passport depending on the bank
Proof of address
A Belgian mobile number for two-factor authentication

Step-by-step

1
Wait for the national register number
Most banks will not complete onboarding without it. Some will open a limited account on a Bijlage 15 and passport, but policy differs by bank and even by branch — ask before booking an appointment.
In personWho: YouAfter city registration
2
Compare on fees, not on brand
KBC, Argenta and Crelan have deep branch coverage in West Flanders; BNP Paribas Fortis, ING Belgium and Belfius are national. Nearly all charge an annual account fee plus card fees, and the standardised fee document they are obliged to give you is the honest comparison.
OnlineWho: You
3
Book the appointment rather than walking in
Branch networks in smaller Flemish cities have thinned considerably and several branches now open limited hours or by appointment only. Turning up on spec with a folder of documents is how a first week gets wasted. Book, and ask on the phone whether the adviser can conduct the appointment in English.
OnlineWho: You
4
Activate itsme as soon as the eID arrives
itsme is the key to MyMinfin, ziekenfonds portals, city e-services and most bank logins. Activation normally needs a Belgian eID with its PIN, or a Belgian bank card and reader. Until then you will be doing in person what residents do on a phone.
Mobile appWho: You
5
Get a Bancontact debit card and expect it to be the default
Bancontact is the domestic debit scheme and is accepted almost everywhere, including small shops, market stalls and surgeries that may refuse a foreign Visa or Mastercard. Payconiq QR payment runs alongside it. Tourist-facing businesses in the centre take everything; the ordinary ones a street back are less certain.
Mobile appWho: You
6
Invoke the basic banking service if you are refused
Belgian law gives residents a right to a basic banking service with essential payment functions. Newly-arrived foreign residents are exactly the group most often refused on internal risk criteria, and most simply try elsewhere rather than knowing the entitlement exists.
In personWho: You

Documents you’ll need

eID, or Bijlage 15 with passport
National register number
Proof of address
Employment contract or enrolment certificate, sometimes requested
Tax residence declaration (FATCA/CRS), always requested

Things most newcomers don’t know

itsme gates Belgian digital life and obtaining it is circular.

Tax filing, health fund portals, city e-services, pension records and most bank logins run through itsme. Activating it normally requires a Belgian eID and PIN, or a Belgian bank card and reader — and the eID requires city registration, which requires the police check. Arrivals hit this loop in week three and conclude the country is obstructive. It is simply sequential: city, register number, eID, itsme, then everything opens at once.

Source: community-reported; FPS Home Affairs

In a smaller Flemish city, the branch appointment is the bottleneck rather than the paperwork.

Belgian retail banking has been closing and consolidating branches for years, and outside the big cities the surviving ones run shorter counter hours and appointment-only slots. The documents are the same everywhere; what differs is that a walk-in that would work in Antwerp will not work here, and the next slot may be a week out. Book from abroad if you can, and confirm the appointment can be held in English rather than assuming.

Source: community-reported

There is a legal right to a basic banking service if a bank turns you away.

Belgian law obliges the sector to provide residents with a basic account offering essential payment functions. Refusals of foreign residents in their first months are common and usually generic rather than personal. Naming the entitlement converts many soft refusals on the spot, and there is a formal route when it does not — most newcomers never learn it exists and just try the next bank.

Source: FPS Economy

Bancontact, not your international card, is the one that always works.

The domestic debit scheme is accepted essentially everywhere, including bakeries, market stalls and doctors' surgeries where a foreign-issued credit card can fail. The tourist centre of Bruges will take any card in the world; the bakery in Sint-Kruis where you will actually buy bread is a different proposition. Carry some cash until the Belgian debit card lands.

Source: community-reported