Before you start

A passport or EU/EEA ID card, shown for prepaid and sometimes for contracts
An unlocked handset, or one that supports eSIM
A Dutch IBAN for a monthly contract's direct debit
A BSN for most SIM-only contracts; handset bundles also trigger a BKR credit check

Step-by-step

1
Buy prepaid on day one and stop worrying about it
There is no SIM-registration law here, so a prepaid SIM from Albert Heijn, HEMA or a Vodafone or Odido shop works within minutes with no form to fill in. Lebara is the usual newcomer choice because its packs and support are in English.
In personWho: YouSame day, about 15 minutesSIM around €5-20 plus a bundle
2
Move to a SIM-only contract once the IBAN exists
SIM-only plans are cheaper per gigabyte and most are cancellable monthly. They require a SEPA direct-debit mandate on a Dutch account and usually your BSN. This is why the phone contract sits third in the chain after registration and banking.
OnlineWho: YouSIM arrives in 1-3 working daysFrom roughly €6-8 per month
3
Use an MVNO rather than a flagship store
Simyo runs on KPN's network, hollandsnieuwe on Vodafone's, and Simpel, Ben and Lebara resell the big three. Coverage is the same physical network at a fraction of the price. The only reason to pay a carrier premium is a bundled TV or fixed-line package you actually want.
OnlineWho: YouSame day to orderTypically half or less of a carrier plan
4
Find out whose contract the internet actually is
If you are renting a self-contained flat, ask whether the building has fibre, coax or only copper before signing; Nijmegen's postwar reconstruction means most of the city is well served, with pockets in the Benedenstad and the pre-war west where it is patchier. If you are renting a room, the connection almost certainly belongs to the landlord or the house and is included in the all-in rent — ask what speed it actually is and how many people share it.
OnlineWho: You, before signingAsk at viewingRoughly €40-60 per month for your own line
5
Watch for German roaming on the eastern edge
Handsets in the Ooijpolder, on the eastern dyke roads and out towards Groesbeek and Beek will sometimes latch onto a German network. EU roaming rules mean it costs nothing extra within your allowance, but fair-use limits exist and calls can behave oddly. If you live or work on that side, lock the network to a Dutch operator in your phone settings rather than leaving it automatic.
Mobile appWho: YouOnce, in settingsFree

Documents you’ll need

Passport or EU/EEA ID card
Dutch IBAN, for a contract's direct debit
BSN, for most SIM-only contracts
Proof of address, for a fixed-line installation

Things most newcomers don’t know

There is no SIM registration in the Netherlands, which is unusual in Europe and genuinely useful on day one.

Most European countries require an identity document to be recorded against a SIM before it activates, which for a newcomer without local paperwork can mean days of delay. Here you walk into a supermarket, pay cash, and have a working Dutch number before you have a Dutch address. It removes any pressure to sign a bad contract in your first week.

Source: community-reported

The Dutch IBAN, not the SIM, is the real gate on a cheap phone plan.

Almost every SIM-only contract bills by automatische incasso, which requires a Dutch bank account, and most providers also ask for a BSN. That puts the chain in a fixed order: address, then gemeente registration, then BSN, then bank, then contract. Trying to jump to the end is where most first-fortnight frustration in the Netherlands comes from.

Source: community-reported

In a room let, the internet is a shared resource you have no contractual say over.

Most Nijmegen rooms come with an all-in rent that bundles utilities and a connection belonging to the house or the landlord. That is fine until eight people are on one 100 Mbit line and you have a standup at nine. You cannot upgrade a contract you are not party to. Ask at the hospiteeravond what the line is and how many people are on it — it is a more revealing question than it sounds, and the answer tells you something about the house.

Source: community-reported

A handset bundle puts you on the BKR credit register; a plain SIM-only usually does not.

Buying a phone on instalments through a mobile plan is treated as consumer credit and is registered with the Bureau Krediet Registratie. That registration is visible to mortgage lenders and can reduce how much you may borrow later. Buying the handset outright and taking a separate cheap SIM-only plan avoids it entirely and is usually cheaper anyway.

Source: BKR

Common mistakes to avoid

Trying to sign a SIM-only contract before you have a BSN and a Dutch IBAN, and being rejected at the direct-debit step.
Paying flagship carrier prices for exactly the same network an MVNO resells.
Taking a handset bundle and picking up a BKR credit registration that later affects a mortgage.
Moving into a room without asking what the shared internet line actually is.
Cancelling the old contract before the number port completes and losing the number.

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