Before you start

Your original passport (a photocopy is not accepted) to register any SIM
For a postpaid SIM-only plan: typically a work pass / FIN, sometimes a local bank account or card for billing
An unlocked, compatible phone (eSIM-capable if you want an eSIM)

Step-by-step

1
Buy a prepaid tourist SIM on arrival
Singtel (hi!), StarHub, and M1 sell prepaid tourist SIMs at Changi (all terminals) and convenience stores. A ~S$12 tourist SIM typically gives around 100GB for 14–30 days. You register on your passport at the point of sale; an eSIM works the same but still needs passport registration to activate.
In personWho: YouMinutes at the counter / instant for an eSIMTourist SIM ~S$12 (around 100GB, 14–30 days)
2
Note the 30-day passport rule
Since 15 July 2024 a SIM registered on a foreign passport is valid for only 30 days. To keep the number you must re-register in person within 30 days using a Singapore IC or work pass — otherwise the line is suspended with no refund. Plan to switch once your pass arrives.
In personWho: YouWithin 30 days of registering on a passport—
3
Move to a SIM-only plan once you have your pass
With your work pass and FIN, switch to a no-contract SIM-only plan from an MVNO — Circles.Life (on M1), GOMO (on Singtel), or giga (on StarHub) — or postpaid direct from the three carriers. Plans run roughly S$10–13/month for 100–350GB with 5G. Postpaid often needs a pass and a billing card or credit check, so the FIN matters here.
OnlineWho: YouSign up online; SIM posted or eSIM activated same daySIM-only ~S$10–13/month (100–350GB); small ~S$2 upfront on some
4
Activate, register, and port your number if needed
Complete registration with your FIN/pass, activate the SIM or eSIM, and (optionally) port your tourist-SIM number across so you keep it. Top-ups and plan changes are handled in each provider's app.
Mobile appWho: YouSame dayPorting usually free

Documents you’ll need

Original passport (for the initial prepaid registration)
Work pass card / FIN (to re-register or take a postpaid plan)
A debit/credit card or local bank account for postpaid billing
Compatible/unlocked phone (eSIM-capable if using eSIM)

Things most newcomers don’t know

A passport-registered SIM lasts only 30 days — then re-register with your pass.

Since 15 July 2024, IMDA rules cap a foreign-passport prepaid registration at 30 days. Miss the in-person re-registration with your IC or work pass and the line is suspended with no refund, so treat the tourist SIM as a stopgap.

Source: IMDA / carrier prepaid terms

The cheapest value comes from MVNOs, not the headline carriers.

Circles.Life (M1), GOMO (Singtel), and giga (StarHub) ride the same three networks but sell no-contract SIM-only plans around S$10–13/month for 100–350GB — far cheaper per GB than a flagship postpaid contract, with the same coverage.

Source: MoneySmart / provider plans

Postpaid usually wants your pass and a billing method; prepaid does not.

Prepaid is pay-as-you-go with spending control and no credit check, which is why it suits day one. Postpaid and many SIM-only plans expect a work pass/FIN plus a local card or bank account (and sometimes a credit check), so they fit once you're settled.

Source: Circles.Life — prepaid vs postpaid

Data is cheap and fast, and eSIM is everywhere.

100GB+ plans for the price of a couple of hawker meals are normal, 5G is widely available, and all three networks plus the MVNOs support eSIM — so you can activate online before you even reach a shop.

Source: StarHub / M1 / Singtel

Common mistakes to avoid

Treating the passport prepaid SIM as permanent — it dies at 30 days without re-registration
Buying an expensive carrier postpaid plan when an MVNO SIM-only plan gives the same coverage for less
Trying to take a postpaid plan before your FIN/work pass is ready
Bringing only a photocopy of your passport — the original is required to register