Data Roaming

Most people only find out what roaming costs them after the trip. That's the wrong order.

The gap between plans is wide. With roaming included in the plan, the trip adds nothing to your bill. Without it, data is billed by the megabyte from the moment you land, and the number only shows up afterwards.

Five minutes before you fly is enough to settle it. Here's how roaming works, what the main telcos charge for it, and what to check on your own plan.

What Is Data Roaming?

Data roaming is when your phone uses mobile data on another operator's network instead of your own telco's, which is what happens the moment you land overseas. No telco here owns mobile towers in Bangkok or Sydney, so yours pays the local operators to carry your traffic instead. When you land, your phone borrows their network. Roaming is increasingly built into the plan rather than sold per trip, drawn from a monthly allowance you already pay for. Where a plan carries no allowance, or you go past it, the data is charged at a pay-per-use rate instead.

The term covers more than data. Voice roaming and SMS roaming work on the same principle. But data is the part that runs up your bill, because a phone left to its own devices will sync mail, back up photos and refresh a dozen apps before you've even cleared the arrivals hall.

Two things decide whether roaming is cheap or painful. The first is whether your plan includes a roaming allowance at all. The second is whether you set anything up before you flew. Miss both and your phone still connects, just at whatever the default rate happens to be.

How Does Data Roaming Work?

Behind the scenes, it's a handshake. Your SIM or eSIM carries an identity that says which network you belong to. When you arrive overseas, your phone scans for available networks, finds one your telco has a partnership with, and asks to join. The foreign network checks with your home network, gets a yes, and lets you on.

From that moment, every megabyte you use is logged by the foreign operator and billed back to your telco, which passes it on to you. That's why the charge turns up on your Singapore bill and not as a separate invoice from an operator in Japan.

A few practical things follow from that:

Data roaming has to be switched on. It's a toggle in your phone's settings. With it off, your phone will still handle calls and SMS abroad, but it won't pull any mobile data.
Your phone picks the network, not you. Most phones do this on their own, joining whichever network your telco has an agreement with that has the strongest signal where you are standing. You can choose manually in settings, which occasionally helps near borders where the wrong network keeps grabbing your signal.
Coverage follows the partner operator. Your telco's islandwide coverage at home says nothing about the patchiness of a rural area in Vietnam. That's the host network's problem, and it becomes yours.
Speeds are the host's speeds. A 5G plan in Singapore doesn't guarantee 5G in Prague. You get whatever the partner network runs and whatever the roaming agreement allows. What separates the two generations is covered in LTE vs 5G.

Data Roaming vs Mobile Data

Same function, different network, different price tag. Mobile data is your phone using your own telco's network in Singapore, drawn from the allowance you already pay for each month. Data roaming is your phone using a foreign operator's network, drawn from a separate roaming allowance or charged on top of your bill. The two pools stay separate. Data you use overseas comes out of the roaming allowance, not the local allowance you pay for every month, and that local allowance cannot be spent abroad unless your plan says the country is covered on base data.

The confusion exists because your phone makes no fuss about the switch. Nothing changes on screen except the carrier name in the status bar. Your apps behave identically. Instagram doesn't warn you that this particular reel is being served over a network in Seoul. That's precisely how people burn through a roaming allowance in an afternoon.

There's one Singapore wrinkle worth knowing, and it catches out a lot of people who assume every border crossing means roaming. Some plans let your ordinary monthly data work in another country outright, with no roaming allowance involved. The 400GB, 500GB and 1TB plans cover Singapore and Malaysia on base data, gigaFLEX+ adds Indonesia and Thailand, and the 6-month 3TB plan adds Indonesia. Drive up to Johor on one of those and you aren't roaming in the billing sense at all. You're just using your plan.

Data Roaming Plans in Singapore

Singapore telcos handle roaming in two broad ways. Some build an allowance into the monthly plan so you travel on data you've already paid for. Others sell roaming as a pass you buy per trip. Plenty do both. Here's what each provider offers, starting with giga. Each one is labelled by how it sells roaming: included in the plan, bought per trip, or both. For the full plan-by-plan picture against individual telcos, see giga vs Singtel hi and giga vs ZYM.

giga Roaming

Included in the plan, with top-up packs.

Every giga plan comes with free monthly roaming built in, so the top-up packs are there for the trips that go beyond it.

Here is what comes included:

Asia Roaming: Malaysia, Indonesia, Thailand, India and South Korea, on every plan.
International Roaming: 48 global destinations, on the 5G plans from 400GB upwards.

Rollover: unused data carries into the next two renewal cycles on the monthly plans and the next cycle on the 6-month plans, and it keeps the same destination scope as your base data.
Both allowances: refresh every month, forever, not as a 12-month teaser.

What each plan includes:

100GB 4G: Singapore data, plus 2GB Asia Roaming, at $10.90 a month.
200GB 4G: Singapore data, plus 4GB Asia Roaming, at $12.90 a month.
300GB 5G: Singapore data, plus 8GB Asia Roaming and no International Roaming, at $15.90 a month.
400GB 5G, for ages 15 to 29: Singapore and Malaysia data, plus 12GB Asia Roaming and 4GB International Roaming, at $11.90 a month.
400GB 5G: Singapore and Malaysia data, plus 10GB Asia Roaming and 6GB International Roaming, at $18.90 a month.
500GB 5G: Singapore and Malaysia data, plus 12GB Asia Roaming and 10GB International Roaming, at $20.90 a month.
gigaFLEX+ 800GB 5G: Singapore, Malaysia, Indonesia and Thailand data, plus 12GB Asia Roaming and 10GB International Roaming, which is 22GB of roaming before you spend anything extra, at $19.90 a month.
1TB 5G: Singapore and Malaysia data, plus 16GB Asia Roaming and 12GB International Roaming, at $28.90 a month.
600GB 4G, 6-month: Singapore data, plus 12GB Asia Roaming, with the whole pool fronted for the six months, at $59.90.
3TB 5G, 6-month: Singapore, Malaysia and Indonesia data, plus 66GB Asia Roaming and 48GB International Roaming, with the whole pool fronted for the six months, at $109.90.
6TB 5G, 6-month: Singapore and Malaysia data, plus 96GB Asia Roaming and 72GB International Roaming, with the whole pool fronted for the six months, at $139.90.

giga also sells destination travel eSIMs on its Shopee store, which are bought per trip and sit outside the roaming that comes with your plan.

gigaRoam Top-Up Packs

When you need more, gigaRoam packs are available to all giga customers and auto-activate the moment you're overseas, so there's nothing to remember at the airport:

APAC: 1GB for $5, valid 5 days, across 14 countries including Japan, Australia, China, Taiwan, Hong Kong and Vietnam.
Global: 1GB for $15, valid 15 days, across all 48 destinations.

The 6-month plans work slightly differently and suit anyone who travels in bursts. The 3TB plan at $109.90 fronts the entire pool up front, 66GB of Asia Roaming and 48GB of International Roaming, for you to spend across the full six months however your travel falls.

eight Roaming

Included in the plan. eight is giga's sister brand and runs on the same StarHub network, so coverage at home is identical between the two.

Here is what comes included:

Roaming on every plan: it comes with the plan rather than being sold per trip, as a monthly APAC Roaming allowance and a monthly International Roaming allowance, each sized by plan.
APAC Roaming: 20 countries on the 5G plans and 8 on the entry plans.
International Roaming: four groups, with Group A covering 68 countries including the United States and most of Europe, and Groups B, C and D covering a further 78 between them.
Local data abroad: the local data on the 5G plans is usable in Singapore, Malaysia, Indonesia, Thailand and Hong Kong.

Extra roaming data is bought in the eight app as 1GB packs, priced by which region group the destination falls into. A pack lasts until your plan renewal date, not for a set number of days.

Singtel ReadyRoam

Both: packs per trip, and an allowance on the higher-tier plans.

Singtel sells roaming as ReadyRoam packs, split by how far you're going. Neighbours covers Malaysia, Indonesia and Thailand, Asia covers 19 destinations, Worldwide covers 135, and an Others tier reaches 210. The Worldwide pack is $40 for 6GB over 30 days.

Roaming also comes bundled on Singtel's higher-tier postpaid plans. Roam Worldwide is included on Enhanced M, Priority L, Priority Pro and Priority FAM; Roam Asia is included on Enhanced Core, Priority Plus and Priority Ultra. Every Singtel mobile plan runs AutoReadyRoam, which activates and charges the next pack automatically once your included data is used up.

StarHub DataTravel

Bought per trip.

StarHub sells DataTravel passes to its postpaid customers across three tiers. Asia Pacific covers 20 destinations, Global adds the United States, Canada, the UAE and most of Europe, and Everywhere reaches up to 195 destinations in total. Prices run from $6 for a short Asia Pacific pass up to $80 on the Everywhere tier, and a 4x data promotion is running until 31 December 2026.

Once a pass is used up, data is charged per megabyte with a daily cap of $30, which gives unlimited data until midnight Singapore time across nearly 150 destinations.

M1 Data Passport

A monthly subscription that unlocks your own plan data.

M1 takes a different route. Data Passport is a monthly subscription, not a one-off pass, and instead of giving you a separate roaming allowance it unlocks your existing plan data for use in the destinations you choose.

A single destination is $15 or $35 a month depending on the country, ASEAN across nine destinations is $35, and the Asia and Europe multi-destination tiers are $65 a month each. It renews monthly until you cancel and carries a one-time activation fee.

Circles.Life Roaming

Included in the plan, on the upper tiers only.

Circles.Life bundles roaming into the plan too, with no pack to buy before a trip, but only on its upper tiers. The Core plans carry no roaming allowance. Circles Plus at $18 a month includes 8GB of Asia Roaming across 7 markets, and the Pro and Ultra plans carry Global Roaming across 15 markets.

Extra roaming data is bought as a boost inside the Circles.Life app. Pricing for those boosts is not published on the website.

Roaming vs Travel eSIM

Roaming on your own plan is one of three ways to get data overseas, alongside a travel eSIM you download before departure and a local SIM you buy on arrival. Which one suits you comes down to four things: how long you are away, how much data you expect to use, how many countries you are visiting, and whether you need calls and texts to keep reaching your Singapore number. A weekend in KL and a month across Europe pull those four in different directions, so each option below says who it is for.

Roaming on Your Existing Plan

Best for short trips, multi-country trips, and anyone who needs their Singapore number to keep working.

You keep your number, you keep your apps, and nothing about your phone changes when you land. Calls and SMS still reach you, which matters more than people expect once a bank wants to send an OTP or a colleague needs you on short notice.

This is the path of least effort, and on a plan with a decent included allowance it's also usually the cheapest. It stops being cheap the moment you exceed the allowance without a top-up in place, which is the whole argument for checking before you fly rather than after.

A Travel eSIM Bought From an App

Best for long stays and heavy data use, on a dual-SIM phone.

Travel eSIM providers sell you a data-only profile you download before departure. You get a local data connection at local-ish prices, which suits long trips and heavy use.

The trade-off is your number. A travel eSIM gives you data, not your Singapore line, so anyone calling or texting your normal number reaches you only if your home SIM is still active alongside it. On a dual-SIM phone that's fine. It also means managing two profiles, two sets of settings and one more thing to get wrong late at night in an unfamiliar airport.

Worth knowing: every giga plan is already eSIM-enabled and already includes roaming. If an eSIM is what you were after, you have one, and it's the same line your friends already call. The two formats are set side by side in eSIM vs Physical SIM.

A Local SIM Card Bought Overseas

Best for a long stay in one country, if you can do without your Singapore number.

Buy a prepaid SIM at the destination airport and you'll often get the cheapest per-gigabyte rate available anywhere. For a long stay in one country, that's a real saving.

It's also the most faff. You queue, you hand over your passport, you swap out your Singapore SIM and hope you don't lose it, and your own number goes dark for the trip. For anything under a fortnight, a gigaRoam pack at $5 for 1GB across 14 APAC countries usually costs less than the taxi you'd take to go and find the shop.

How Much Does Data Roaming Cost?

It depends almost entirely on how you buy it, and the spread is much wider than people assume.

Pay-per-use is the expensive end. With no allowance and no pass, your phone connects at your telco's default rate, charged per megabyte or per day, and those rates vary by operator and destination. It's the setting that produces the horror stories, because nothing stops it running while you sleep.

A roaming pass is the middle ground. You pay a fixed amount for a fixed amount of data over a fixed window, and you know the number before you go. giga's APAC pack is $5 for 1GB over 5 days; the Global pack is $15 for 1GB over 15 days.

Included allowances are the cheap end, because the marginal cost of the trip is nothing. On gigaFLEX+, 22GB of roaming data a month is already in the $19.90 you were paying anyway, whether you travel or not.

For most short-haul trips, included roaming plus one top-up pack is both the cheapest route and the least hassle. The gap only closes on a long stay in a single country.

Why Is Data Roaming So Expensive?

Because you're paying two companies, not one. The foreign operator charges your telco a wholesale rate for carrying your traffic, and your telco adds its own margin on top. There's no equivalent of the EU's capped roaming rules across Asia-Pacific, so those wholesale rates are negotiated network by network and vary a lot by country.

Then there's the granularity. Pay-per-use roaming is often billed in small increments with rounding, so a handful of background app refreshes across a day costs more than the data volume suggests it should. Add a phone doing photo backups over a foreign network and a modest-sounding daily rate compounds fast.

This is also why an allowance built into the monthly plan behaves so differently. The wholesale rate has already been absorbed into what you pay each month, so the trip itself adds nothing.

How Much Roaming Data Do I Need?

Work backwards from what you will actually do on the trip, because video decides almost everything.

Maps, chat and the odd search: the lightest use there is. Navigation and messaging barely register, so a week of finding your way around a city and staying in touch sits comfortably inside 1GB.
Social feeds and photo uploads: the middle of the range, and the most common reason an allowance empties faster than expected. Feeds are mostly autoplaying video now, so scrolling costs more than it feels like it should.
Streaming and tethering a laptop: the heavy end. Netflix puts its own mobile figures at about six hours of viewing per gigabyte on the data saver setting, and up to 1GB every 20 minutes at maximum quality. Tethering adds a second device to the same allowance.

In practice, a short trip spent on maps and messaging usually fits inside the Asia Roaming allowance already on your plan, with a $5 gigaRoam APAC pack as the buffer. A longer trip, or one where you expect to stream, is better sized against a monthly allowance than a per-trip pack, because 1GB is an hour of standard-definition video and not much more.

How to Avoid Data Roaming Charges

None of this requires any technical skill. It comes down to one decision when you choose your plan, and two habits while you are away.

Choose a Plan With Roaming Already Included

The single most effective move, and the one people skip because they pick a plan based on local data alone. If your plan already carries a monthly roaming allowance, the decision is made before the trip starts.

Every giga plan includes Asia Roaming across Malaysia, Indonesia, Thailand, India and South Korea, and the 5G plans from 400GB upwards add International Roaming across 48 destinations. It refreshes every month and it doesn't expire after a promotional year, so the plan you chose for Singapore is already the plan you travel on. What each tier includes is listed on giga's plans page.

Monitor or Cap Your Roaming Data Usage

Watch the number, don't guess at it. The giga app shows your roaming balance in real time alongside your local data, so you can see the allowance draining on day two instead of discovering it on the bill.

Your phone helps too. Both iOS and Android let you see data use per app, so you can tell which one is doing the spending.

Cut What Your Phone Uses Overseas

Most roaming data goes on things you never asked for. Three habits cover almost all of it.

Download what you can before departure: offline maps for the city, playlists, and whatever you plan to watch on the flight. Google Maps lets you save an area for offline use, and one downloaded series saves more data than every other tip here.
Turn off automatic app updates and cloud photo backups: left on their defaults, a phone will update apps in the background and push a week of holiday photos to the cloud, all of it over your roaming allowance. Switch both back on when you are home on Wi-Fi.
Use aeroplane mode when you do not need to be reachable: on a long coach ride, a hike or overnight, it stops everything at once, and Wi-Fi can be switched back on separately while it is enabled.

Why Choose giga?

No contracts, no hidden fees, and roaming that is already in the plan. On roaming specifically, a few things set giga apart.

Free Rollover Data That Travels With You

Every giga plan rolls over unused data, and it's free on all of them. Whatever you don't use carries into the next two renewal cycles on the monthly plans, and into the next cycle on the 6-month plans, so a quiet month funds a busy one. On the 800GB gigaFLEX+ plan that means up to 1.6TB available at once.

Rolled-over data keeps the same destination scope as your base data. On the 400GB, 500GB and 1TB plans that means it still works across Singapore and Malaysia, on the 300GB plan Singapore only, and on gigaFLEX+ across Singapore, Malaysia, Indonesia and Thailand. The data you saved by staying in last month is the data you use in Johor this month.

Roaming Included on Every Plan, Not Sold as an Add-On

Roaming isn't an upsell at giga, it's in the plan. Asia Roaming across five countries comes with every plan, and International Roaming across 48 destinations comes with the 5G plans from 400GB up. It refreshes monthly, forever.

That changes how the trip feels. There's no pass to remember, no window to activate, and no scramble at the gate. You land and your data is already there.

Real-Time Roaming Tracking, Plus Free Data Drops in the App

The giga app shows your roaming balance as it moves, not a day later. That alone prevents most bill surprises, because the thing people actually want abroad is to know where they stand.

The app is also where giga gives things away. gigaSurprises drop extra data without you asking for it, including on your birthday and on the occasional random Monday, and there are monthly giveaways running through giga's social channels. Refer a friend and you get $6 in gigaBucks with no cap on how many times, while they get $6 off their first month. gigaBucks come straight off your next bill.

No Bill Shock and No Hidden Roaming Fees

No contracts, no lock-in, no activation charges, and no roaming fees hiding in the small print. What the plan says it includes is what you get, in Singapore and overseas.

gigaRoam packs are priced the same way. $5 for 1GB across APAC, $15 for 1GB globally, auto-activated when you land so there's no window to miss and no accidental pay-per-use running in the background.

How to Switch to giga and Port Over Before You Fly

Porting over to giga is designed to take minutes, not days. You sign up in the giga app, keep your existing number through number transfer, and activate with one tap. Every plan is eSIM-enabled, so there's no waiting for a physical SIM to arrive and nothing to collect. Setup steps are on giga's eSIM page.

That matters more than usual when a trip is close. Switch and activate the eSIM the night before, and you land with your roaming allowance already live on your usual number.

FAQs

Which countries are included in giga roaming?

Two lists. Asia Roaming, included on every plan, covers Malaysia, Indonesia, Thailand, India and South Korea. International Roaming, included on 5G plans from 400GB upwards, covers 48 destinations across Asia, Europe, the Middle East, North America and Oceania. gigaRoam top-up packs cover 14 APAC countries on the $5 pack and all 48 destinations on the $15 pack.

Can I use my Singapore data in Malaysia?

On most giga 5G plans, yes, and not as roaming. The 400GB, 500GB, 1TB and gigaFLEX+ plans all include Malaysia in their base data, so your normal monthly allowance works across the Causeway. gigaFLEX+ adds Indonesia and Thailand on top. The 300GB plan is Singapore-only on base data, so Malaysia comes out of its 8GB Asia Roaming allowance instead.

Does data roaming work in China?

Yes, though not through the Asia Roaming allowance, which covers five countries and doesn't include China. China is in giga's 48-destination International Roaming list, so 5G plans from 400GB upwards cover it out of the monthly allowance. On any other plan, the gigaRoam APAC pack at $5 for 1GB includes China.

Does data roaming cover calls and SMS too?

No, and on giga that distinction matters more than usual. giga does not offer roaming call or SMS packs, and only roaming data services run on the plan overseas. Your monthly roaming allowance and any gigaRoam pack cover data and nothing else. The talk time and SMS allowances that come with your plan are for use in Singapore.

Will I be charged if data roaming is on but I do not use it?

Not for simply having it switched on. You're charged for data your phone actually transfers. The catch is that "not using it" is rarely true: background app refresh, email sync and cloud photo backup all count as usage, and they run without you touching the phone. If you want the toggle on but the spend controlled, turn off background refresh for your heaviest apps first.

Can I still receive bank OTPs and SMS with data roaming off?

Yes. SMS arrives over the voice network rather than mobile data, so OTPs still reach you with data roaming switched off. On giga, incoming SMS overseas is free, and not only across the 48 roaming destinations: it works in more than 230. Bank apps that push a notification instead of an SMS are the exception, since those need a data connection or Wi-Fi.

Does a travel eSIM need data roaming switched on?

Usually yes, because a travel eSIM connects to a partner network, not one of its own. Check that the data roaming toggle is enabled for that specific eSIM profile and not for your Singapore line, which is the step most people miss. On giga, your plan's roaming is already active on your own line, so there's no second profile to configure.

Do I need data roaming to use Wi-Fi calling while overseas?

No. Wi-Fi calling routes over a Wi-Fi connection rather than a mobile network, so data roaming can stay off. Your telco and your phone both need to support it, and it has to be enabled in your settings before you travel.

Should I have data roaming on or off?

On, if your plan includes a roaming allowance or you've bought a pass, because you've already paid for the data and leaving it off just means you can't use it. Off, if you have neither and don't want pay-per-use charges running in the background. The better question is what your plan covers, and that's worth five minutes before the trip rather than five minutes of regret after it.

How do I turn data roaming on or off?

On an iPhone, go to Settings, then Mobile Data, then Mobile Data Options, and switch Data Roaming on or off. On Android, it sits under Settings, then Connections or Network and internet, then Mobile networks, then Data roaming. If your phone carries more than one SIM or eSIM, the toggle is set per line, so check you are changing the right one. Leaving it on only costs you if your plan has no roaming allowance and no pack attached to it.