SIM-only plans in Singapore: how to compare the real cost

The cheapest SIM-only plan is the one with the lowest total over the months you will really keep it, not the one with the lowest first-month price or the biggest data number. Add every monthly fee, include one-off charges, subtract any credit, then compare plans on the same footing and note what it would cost to leave early.

This guide gives that method and does not quote plan prices. The method and worksheet are ours. Operators’ plan pages could not be opened when this guide was researched on 3 October 2026 and were not reopened for its recheck on 17 October 2026, and promotions change often, so any price printed here would be unverified. The worked-example figures are illustrative, not real offers.

What do IMDA’s guidelines say about contract length and leaving early?

IMDA’s Contract Period and Early Termination Guidelines are advisory. IMDA says they describe how it will generally apply sub-sections 3.2.4 and 3.4.4 of its Code of Practice for Competition in the Provision of Telecommunication and Media Services 2022, that the Code prevails if the two differ, and that the facts of each case are considered. They say:

• Contract period: IMDA considers that contract periods should be limited to no more than 24 months.
• Graduation: for a contract longer than three months, the early termination charge (ETC) should be graduated on at least a month-by-month basis, so it falls as the months left fall. A fixed charge on such a contract would not be considered “reasonably proportionate”; IMDA does not object to a fixed ETC where the contract period does not exceed three months.
• Ceiling: the ETC should exclude costs the operator avoids when you leave, should be reasonably below the sum of the monthly fees for the remaining months, and in all cases cannot be higher than that sum.
• Disclosure: operators must tell you the contract period and ETC before you subscribe, and IMDA says they should obtain your express written acknowledgement that you understand the ETC. Its illustration is a signed one-page summary of key prices, terms and conditions.

IMDA’s own illustration is a 24-month mobile contract with a S$200 ETC if cancelled straight after signing up. At 18 months, the ETC should be no more than 6/24 × S$200 = S$50, minus the operator’s avoidable costs.

These are guidelines, not a promise about any particular plan, and they concern agreements with a contract period. Whether a plan has one is set out in the operator’s own terms, which we did not read.

Which SIM-only plan is cheapest? Work it out over 24 months

This worksheet is ours, not IMDA’s or CCS’s. Fill in the same lines for each plan. We use 24 months because it is the longest contract period IMDA’s guidelines contemplate; use fewer if you expect to switch sooner.

• The monthly fee for each month, including any introductory price and the date it ends
• One-off charges, such as a SIM or activation fee, delivery or a deposit
• Credits, vouchers or free months, and any condition attached to them
• The contract period, and whether the plan renews automatically afterwards
• If there is a contract period, the ETC in dollars at month 6, month 12 and month 18 (ask for the figures rather than assume them)
• What happens to your speed, data or bill when you pass the quota or travel

Total cost = all monthly fees + one-off charges − credits. Divide by the number of months to get an average monthly cost.

Here is a worked example with fictional plans and illustrative figures.

• Plan A: S$10 a month for the first 6 months, then S$25 a month. No one-off fee.
• Plan B: S$20 a month throughout, plus a S$10 activation fee.

Over 24 months, Plan A costs 6 × S$10 + 18 × S$25 = S$510, an average of S$21.25 a month. Plan B costs 24 × S$20 + S$10 = S$490, about S$20.42 a month. Plan B is S$20 cheaper over two years, although Plan A has the lower running total through month 19.

The break-even matters more than either total. After n months (n above 6), Plan A has cost 25n − 90 and Plan B has cost 20n + 10. The two are equal at n = 20, when each has cost S$410. If you expect to keep the line for fewer than 20 months, Plan A is cheaper; beyond 20 months, Plan B is. Our inference: if you leave at month 6, Plan A has cost S$60 against Plan B’s S$130, but only if leaving then carries no ETC.

Now the exit charge. Suppose Plan A were a 24-month contract and you left at month 12. The outer limit is the S$300 of fees still to come (12 × S$25), and IMDA says the charge should be reasonably below that. If Plan A’s ETC at signing were S$200 (our assumption), IMDA’s illustration method, which scales the starting ETC by the share of the contract still to run, gives at most 12/24 × S$200 = S$100, minus avoidable costs. Ask the operator for the actual figure.

What else changes the real price of a SIM-only plan?

The Competition and Consumer Commission of Singapore’s Guidelines on Price Transparency, last updated 26 September 2025, say suppliers should include unavoidable or mandatory charges, such as taxes, surcharges and service fees, in the total headline price, and that discounts should be genuine. They also encourage an “opt-in” or “opt-neutral” approach to optional add-ons, so consumers actively tick the ones they want, and apply to all suppliers, online or in stores. We use them as a yardstick when a plan page leaves things out.

Then look for what the headline does not show. This list is ours:

• What happens after the data quota: a slower speed, a charge, or a top-up you must buy
• Overseas use: whether it needs a separate pass or is charged by usage
• Extra lines, add-on bundles or protection plans offered at checkout
• Whether your handset takes the plan’s SIM type, a physical SIM or an eSIM, and whether an older handset still works on the network; our guide to buying a phone overseas covers what IMDA has said about 3G retirement and VoLTE
• What you need to do, and what it costs, to keep your current number if you switch operator (we did not read IMDA’s rules on this, so ask the new operator)

On roaming, IMDA’s data roaming page, last updated 25 May 2026, says that since 1 February 2012 consumers have been able to use a Data Roaming Bill Cap service to suspend data roaming when charges reach a maximum of S$100 every billing month, and that operators are required to obtain explicit consent before providing roaming services. Ask how the cap works on your plan; we did not read any operator’s roaming terms.

Charges that depend on how much you use are easiest to judge by pricing a quiet month and a busy month, the method in TBYB’s guide to comparing AI tool pricing. It works equally well for data you might exceed.

How do I keep a record before I sign?

Offer pages change or disappear, so capture the evidence on the day. Before you check out lists what to save for any purchase, and the year-end total-price check applies the same habits to sale offers. For a phone plan:

1. Screenshot the plan page and the final checkout total, with the date and time visible.
2. Save the one-page summary of key terms if you are given one; if not, ask for the key terms in writing.
3. Write down the date the introductory price ends and set a reminder a month earlier.
4. Keep the order reference and the SIM or eSIM confirmation, and compare your first bill with your total.

If an operator’s terms differ from what you were shown, start with the operator; the consumer rights guide covers the general complaint routes. Our glossary entry on early termination charges gives IMDA’s definition in one place, and our free-trial cancel-path test shows how to test the way out of a subscription before you sign up. If promotional texts follow your sign-up, see what shops may send after you buy. IMDA also runs an Alternative Dispute Resolution scheme for telecoms and media disputes; its page, last updated 25 May 2026, gives a S$10,000 limit and a one-year window, asks you to approach your provider first, and excludes decisions about how services are priced. Check it for current criteria.

What to check before you sign

• You have the total for each plan over the months you expect to keep it, not just the monthly price.
• You know when the introductory price ends and what the plan costs afterwards.
• You have the contract period, whether it renews automatically, and the ETC in dollars at months 6, 12 and 18 if there is a contract.
• Add-ons are ones you ticked yourself, and you know what happens past the data quota or overseas.
• Your handset works with the SIM type and network, and you know how to keep your number if you switch (if you are changing handset too, our trade-in and recycling guide covers the old one).
• You have dated screenshots of the offer and checkout total, and a copy of the key-terms summary if you were given one.

More comparison methods are on the comparing topic page.

Common questions