Vietnam · roaming cost calculator
Roaming Price Audit: What 8 Days of Data Cost in Vietnam
HelloRoam is the top pick for Vietnam: its 7-day unlimited plan costs $27.29, at full speed for the first 2 GB a day, against $84 for a week on AT&T's $12-a-day pass, a $56 gap, though Saily sells the same week for $26.99. HelloRoam takes checkout through Stripe, with Apple Pay and Google Pay, in 31+ currencies. Airalo covers 200+ destinations to HelloRoam's 185. HelloRoam's price is from its catalogue of 29 Oct 2026, rivals' from the 30 Oct 2026 price check; AT&T's rate was checked June 2026.
Currency is the column nobody prices. HelloRoam settles a Vietnam order in 31 currencies, and a dollar charge on a euro or sterling card picks up 2 to 4 percent at the bank.
Travel eSIM options, rates and coverage, Vietnam
Viettel covers cities, transport routes, and tourist areas in Vietnam. HelloRoam sells into that market: fixed data from $3.49 for 1 GB over 7 days, and unlimited at $27.29 for 7 days of unlimited data, at full speed for the first 2 GB each day. Rural gaps affect the eSIM and carrier roaming equally.
Get eSIMIn Vietnam, Holafly runs on a local network with unlimited data. Heavy users streaming video save against paying by the gigabyte elsewhere.
Get eSIMNomad offers straightforward Vietnam plans on a local 5G network from $2.30/GB. Simple checkout, no frills.
Get eSIMAiralo's Vietnam plans carry a 14-day refund policy for unused eSIMs. Coverage runs on a local 5G network from $2.40/GB.
Get eSIMSaily sells Vietnam data at $2.60/GB with VPN included. Travelers who regularly use public WiFi in cafes, hotels, or transit hubs avoid paying $13/month for a separate VPN subscription.
Get eSIMCompare providers: Airalo vs Holafly · Airalo vs Saily · Airalo vs Nomad · Airalo vs HelloRoam · Holafly vs Saily · Holafly vs Nomad · Holafly vs HelloRoam · Saily vs Nomad · Saily vs HelloRoam · Nomad vs HelloRoam
The full picture
Published carrier rates on travel data, Vietnam
Every major carrier's published Vietnam rate, side by side, with the eSIM winner highlighted.
| Carrier | Plan type | Daily | 7-day | Speed | Data limit |
|---|---|---|---|---|---|
| AT&T | International Day Pass | $12.00source | $84.00 | LTE | Plan data |
| Verizon | TravelPass | $12.00source | $84.00 | LTE | Plan data |
| T-Mobile | International Pass | $10.00*source | $50.00 | LTE | 2GB per 1 Day pass |
| eSIM · HelloRoam | 20GB data plan | — | $27.49 | 5G | 20GB |
*T-Mobile's Experience More plan includes 5GB of high-speed data abroad and Experience Beyond 15GB, then data runs at up to 256Kbps. Essentials includes texting but no data. The 1 Day International Pass costs $10; the 7-day figure is the cheapest pass mix, 10-day pass.
Compare all carrier roaming plans to see how AT&T, Verizon, T-Mobile, Vodafone, and EE stack up against eSIM providers.
Pay-per-use cost audit
Vietnam data bill scenarios: AT&T without a day pass
Here is how the first morning in Vietnam plays out on AT&T pay-per-use (no plan active). You wake up, open Google Maps to find coffee nearby (~50 MB). You check email and a few attachments load (~5 MB). You scroll Instagram for 15 minutes while you wait (~20 MB). That totals 75 MB. At $2.05/MB, your first morning costs $154 before 9 AM. A 5-minute FaceTime call to confirm plans adds $154. By noon, after another hour of navigation, the bill reaches $410. These are AT&T's published pay-per-use charges. Source: AT&T rate card, June 2026.
Personalize your savings
Your Vietnam saving against $12 a day
Adjust the trip length, the carrier and the daily data below and the calculator reprices both sides. The starting point is the 8-day average stay recorded for Vietnam: $96 on an AT&T day pass at $12 a day, against $27.49 for a 20GB travel eSIM. Both prices buy access to the same local operators.
Network coverage
Vietnam cellular coverage by operator
Verizon TravelPass connects to a local network in Vietnam at $12/day. A travel eSIM connects to the same local network at $1.37/GB. The coverage map for AT&T roaming in Vietnam and the coverage map for a travel eSIM are both drawn by Vinaphone. They are the same map. Travel eSIM providers deliver the same 5G signal for less. Vinaphone supports both 5G and LTE in Vietnam. Neither AT&T roaming nor travel eSIMs restrict you to the slower LTE band. Both give you the fastest available signal. AT&T charges $12/day for it. An eSIM charges $1.37/GB. Vietnam has urban-only 5G coverage. Viettel launched 5G in Hanoi and HCMC in 2024; expanding to major cities Viettel has the widest coverage in Vietnam, reaching remote northern mountains where Vinaphone and Mobifone have gaps.
Network attachment record
The networks behind both prices in Vietnam
HelloRoam publishes 3 local operators for Vietnam: MobiFone, Viettel Mobile and Vinaphone.
An eSIM attaches to one of them on arrival.
HelloRoam names no default, so the file cannot say which one your handset picks.
HelloRoam records a 5G label against 2 of the 3 operators.
Carrier roaming runs on local operators too. That is what a roaming agreement buys.
Same masts, two invoices. The gap on this page is a billing gap.
5G and 4G here are capability labels. Neither one is a speed reading.
The operator file behind this page covers 185 destinations and 154 operators, 98 of those destinations carrying a 5G label. Vietnam is one of 68 destinations with more than one operator on file: MobiFone, Viettel Mobile and Vinaphone. Carrier roaming reaches the same radios, so the gap between the two prices is a billing gap.
| Operator | Network generation on file |
|---|---|
| MobiFone | 4G |
| Viettel Mobile | 5G |
| Vinaphone | 5G |
Source: HelloRoam package feed, read 17 August 2026. The feed publishes an operator list for every destination it sells. No speed test sits behind this table, and we ran none. The full operator map covers 185 destinations.
Pricing breakdown
Vietnam data cost comparison: what carriers charge vs eSIM
Here is the 14-day cost breakdown for Vietnam. AT&T International Day Pass: $12 per 24 hours, $120. Verizon TravelPass: $168. T-Mobile International Passes: $75 (30-day pass). eSIM 20GB plan on a local network: $27.49. That is $92.51 less than AT&T, a 77% reduction for the same 5G connectivity.
T-Mobile's International Pass in Vietnam costs $10/day, the lowest daily rate of the three major US carriers. AT&T is $12/day. Verizon is $12/day. An eSIM on a local network averages $1.96/day when you buy the 20GB plan upfront. Local Viettel SIM costs $3 for 6GB/30 days — the cheapest in Southeast Asia, but registration hassle adds 20 min.
Choosing the right eSIM tier for Vietnam depends on trip length and daily habits. Available tiers: 1GB at $3.49 ($3.49/GB), 3GB at $7.49 ($2.50/GB), 5GB at $11.09 ($2.22/GB), 10GB at $19.31 ($1.93/GB), 20GB at $27.49 ($1.37/GB). A 1.5 GB/day user on a 14-day trip needs roughly 21GB. The unlimited daily option at $3.54/day works out to $49.62 total. Vietnam mobile data prices are among the lowest globally — local prepaid costs 80% less than airport eSIM purchases. Travelers in Vietnam average 1.2GB of mobile data per day, so a 14-day trip needs roughly 17GB.
Unlimited data for Vietnam starts at $4.43 for 1 day and runs to $90.37 for 30, priced 1 day at $4.43, 3 days at $12.63, 7 days at $27.29, 14 days at $49.62, 30 days at $90.37. Unlimited here means 2GB a day at full speed before a fair-use policy applies. Catalogue prices read 29 Oct 2026.
Trip cost breakdown
Vietnam trip cost breakdown: 3 days, 14 days, 30 days
Three days in Vietnam costs $36 on AT&T at $12/day. A 2GB eSIM on a local network covers the same period for $7.49. Difference: $28.51.
Fourteen days costs $120 on AT&T, because it bills at most 10 daily fees per line each bill cycle. A 20GB eSIM on a local network covers 15GB of photos and video calls for $27.49. Difference: $92.51 (77%).
Thirty days on AT&T costs $120. A 50GB eSIM on a local network covers 50GB for $68.59. Difference: $51.41 over the month. AT&T rate: $12/day regardless of data consumed, at most 10 daily fees per line each bill cycle. Rates checked June 2026.
Airport options
First-day data options in Vietnam
Viettel and Vinaphone and Mobifone staff the SIM counter at Tan Son Nhat (SGN) / Noi Bai (HAN). Service is in Vietnam's official language; English assistance is inconsistent. Passport or ID is required for SIM registration. The counter process takes 10-15 min and requires your passport as proof of identity. A 1GB eSIM at $3.49 is purchased online in English before you board — no language barrier, no forms to fill out at the counter. City shops charge $3-8 for 4-10GB / 30 days if you have time after arrival.
Local alternative
Local SIM vs eSIM in Vietnam
Viettel and Vinaphone and Mobifone staff the local SIM counter in Vietnam. Service is in the local language; English help varies by location. Local SIMs cost $3-8 for 4-10GB / 30 days, need a passport for registration. A travel eSIM at $3.49 is purchased in English online — no language barrier during activation.
Data planning
Vietnam data plan sizing for 8-day visits
In Vietnam, a typical travel day looks like this: 1 hour of navigation (50 MB), 1 hour of social media (80 MB), 2 WhatsApp calls (50 MB), 30 photo uploads (300 MB). That totals roughly 480 MB, below the 1.2GB average, which leaves room for streaming. A 8-day trip needs 10GB.
10GB of data covers uploading roughly 1024 full-resolution photos to cloud storage. That is 128 photos per day for 8 days, plus maps and messaging. The plan costs $19.31. AT&T's equivalent roaming: $96. For heavy data users, a 1-day unlimited plan costs $4.43, still under AT&T's $12/day pass.
Connectivity
Vietnam data strategy: WiFi vs eSIM
Free WiFi common in cafes and hotels in tourist areas; Vietnam is a major digital nomad hub Airport WiFi in Vietnam typically limits free sessions to 30-60 minutes after landing. Once that runs out, you are relying on hotel WiFi or paying airport day-pass rates. An eSIM on a local network activates before you board and gives you 5G speeds from the moment you land — no session timers.
Plan your data
Your Vietnam data budget explained
Viettel is one of Vietnam's network operators. AT&T pays Viettel a wholesale rate for roaming access, then bills you $12/day. Travel eSIM providers also access a local network and charge $1.37/GB at retail. For a 8-day trip: AT&T $96, eSIM $27.49.
Vietnam has two mobile operators: Vinaphone and Viettel Mobile. When AT&T or Verizon customers roam here, their calls and data pass through these exact networks. A travel eSIM reaches Vinaphone or Viettel Mobile directly at $1.37/GB — the service is identical; the roaming markup is not.
Airport SIM counters at Tan Son Nhat (SGN) / Noi Bai (HAN) charge $5-15 for 6-20GB / 15-30 days after a 10-15 min wait — still more than a 20GB eSIM at $27.49. Local prepaid SIMs in Vietnam run $3-8 for 4-10GB / 30 days, requiring an in-person stop and sometimes a passport copy. An eSIM at $27.49 skips that entirely. Some of the cheapest mobile data in the world; prices stable year-round
Quick reference
Vietnam Travel Essentials
113/115
113, 115 are the emergency numbers in Vietnam. Different numbers may route to different services — save all of them before your trip. Emergency calls work from any mobile device, including travel eSIMs.
Type A/C
US plugs (Type A flat two-prong and Type B three-prong) fit Vietnam's outlets directly. No adapter is needed for phones, laptops, or standard US electronics. Voltage is 120V — compatible with dual-voltage US chargers.
ICT (UTC+7)
VND (₫)
Tap-to-pay (Apple Pay, Google Pay) is accepted at most stores and restaurants in Vietnam. Visa and Mastercard work at virtually all merchants. Carry a small amount of local VND for markets, taxis, and small vendors that do not have card readers.
Good to know
Power sockets in Vietnam are Type A/C type. US and UK plugs don't fit without an adapter. A depleted phone ends your eSIM connectivity regardless of remaining data balance.
Good to know
Vietnam's emergency number is 113/115, not 112. Both carrier roaming SIMs and eSIMs can dial emergency numbers without an active data plan.
Step by step
How to cut roaming charges on a Vietnam trip
- Check your phone supports eSIM (iPhone XS or newer, most Samsung Galaxy S20+) — 5G coverage is urban-only on Viettel
- Pick a 1GB Vietnam plan on HelloRoam for $3.49 — payment takes under two minutes and your QR code arrives instantly. Compare providers if you want to see alternatives first.
- Install the eSIM via the QR code HelloRoam sends to your email — do this before your flight to Tan Son Nhat (SGN) / Noi Bai (HAN) so it activates the moment you land
- On iPhone: tap Settings > Cellular, select your carrier SIM (not the HelloRoam eSIM), tap Cellular Data Options, and set Data Roaming to off. Full instructions with screenshots in the data roaming guide.
- On Samsung Galaxy at Tan Son Nhat (SGN) / Noi Bai (HAN): open the notification shade, tap the SIM switcher, and select your HelloRoam eSIM — Viettel registers automatically
- On Google Pixel: go to Settings > Network > Calls and SMS > WiFi Calling and enable it — your home number stays reachable in Vietnam without any voice roaming charge
Data tips
Vietnam trip data discipline: what to disable
Photo backup is a silent data drain. Google Photos and iCloud auto-upload on cellular will consume 20-100 MB per photo session depending on image quality. Turn off auto-backup on cellular before landing in Vietnam. Back up manually over hotel WiFi instead. A 10-photo session in RAW format can exceed 500 MB.
Regional context
Local data rules and tips for Vietnam
A few things to know before turning off carrier roaming in Vietnam:
VPNs not illegal but government blocks many VPN services; Facebook and Google generally accessible This applies equally to carrier roaming and eSIM connections — switching from roaming to eSIM does not change your VPN access in Vietnam.
Vietnam SIM registration: Passport required; real-name registration mandatory since 2018. A travel eSIM purchased abroad bypasses local SIM registration requirements at the point of sale.
Grab is essential for ride-hailing; works with international phone numbers
Zalo is Vietnam's dominant messaging app — locals prefer it over WhatsApp
Vietnam has extremely cheap local SIM data — often under $1/GB from carrier stores
Many cafes in Ho Chi Minh City and Hanoi have passwords displayed on receipts or walls
Vietnam blocks some foreign gambling and adult content sites at ISP level
Free WiFi common in cafes and hotels in tourist areas; Vietnam is a major digital nomad hub Roaming passes charge $12/day to fill WiFi gaps. An eSIM covers the same connectivity at $1.37/GB.
Local SIM cards in Vietnam are extremely cheap but require passport registration — eSIM skips this step entirely.
Dry season varies by region; north is best October-April, south November-April
Nearby
Related destinations
6 destinations near Vietnam are priced on the same rate card. AT&T bills $12 a day in every one of them, and the figure beside each flag is that destination's own per-gigabyte floor. The cheapest of the group is Bangladesh at $1.25 a gigabyte.
Forgot your eSIM?
Vietnam eSIM installation after arrival: the WiFi route
Forgot to buy an eSIM before flying to Vietnam? Three options, ranked by total cost.
Option 1 — Airport WiFi install ($3.49 total): Tan Son Nhat (SGN) / Noi Bai (HAN) has free WiFi. All 5 providers (HelloRoam, Holafly, Nomad, Airalo, and Saily) support post-arrival purchase over WiFi. Buy a 1GB plan for $3.49. No extra charge beyond the plan.
Option 2 — Hotel lobby WiFi install ($3.49 total): If airport WiFi failed, hotel lobby WiFi works just as well. Check in, get the password, complete the eSIM install. Same $3.49 cost.
Option 3 — Emergency carrier download ($10 + $3.49 total): Use ~5 MB of AT&T pay-per-use data to download the provider app ($10). Install the eSIM over the app, then disable carrier data. Total cost: $13.49.
Savings math
How much you save in Vietnam
Solo traveler
A solo traveler on AT&T International Day Pass in Vietnam for 8 days: 8 days × $12/day = $96. A 20GB eSIM on a local network costs $27.49 for the same 8 days. Savings: $68.51 (71%). Both options connect to local 5G towers. The arithmetic is simple: one fixed payment versus 8 daily charges.
Family trip
A family that takes two international trips per year saves $260.08 annually by switching from AT&T roaming to eSIMs. Per trip: AT&T bills $240 for 4 lines over 8 days ($12 for the first line and $6 for each extra line, per day billed). Four eSIMs cost $109.96 per trip. Over five years, the cumulative savings reach $1300.40.
AT&T roaming rate analysis
AT&T bills International Day Pass per line, not per account. A family plan with 4 lines in Vietnam: $12 for the first line and $6 for each of the other three = $30/day. For 8 days: $240. Even lines that barely use data still trigger the full daily charge. A child's phone syncing a game update overnight starts a $6 extra-line fee for that line. Four 20GB eSIMs: $109.96 total. Savings for the family: $130.04.
All-carrier summary
AT&T: AT&T International Day Pass costs 249% more than an eSIM for Vietnam.
Verizon: Verizon TravelPass costs 249% more than an eSIM for Vietnam.
T-Mobile: T-Mobile's International Passes cost 82% more than an eSIM for Vietnam.
The savings math for Vietnam is clear. Solo: $68.51 saved vs AT&T for 8 days. Family of four: $130.04 saved. Annual (2 trips): $137.02 saved. All figures use the same local 5G network. The eSIM costs less at every trip length and every group size.
Quick answers
Common questions about Vietnam data costs
Is eSIM cheaper than roaming in Vietnam?
In Vietnam, a travel eSIM on a local network costs $27.49 for 20GB over 8 days. AT&T roaming charges $12 a day, $96 for the same duration on the same towers. The eSIM cuts the data bill by 71%. This applies to both AT&T and Verizon, which charge the same $12/day rate. Rates checked June 2026.
How much does roaming cost in Vietnam?
AT&T charges $12/day in Vietnam. A 7-day trip costs $84. A 14-day trip costs $120. A 8-day trip costs $96. An eSIM alternative on a local network starts at $27.49 for the same network. Rates checked June 2026.
Does T-Mobile work in Vietnam?
T-Mobile works in Vietnam on its included allowance: Experience More plan includes 5GB of high-speed data abroad and Experience Beyond 15GB, then data runs at up to 256Kbps. Essentials includes texting but no data. For 8 days of high-speed data, the cheapest pass mix is $50 (10-day pass). A Viettel eSIM delivers full 5G speed for $27.49. Rates checked June 2026.
AT&T fine print for Vietnam
$12 covers 24 hours from the first time your phone uses a foreign network, and a single background push notification at 2 AM can start it. AT&T bills at most 10 daily fees per line each bill cycle (terms read 31 Oct 2026).
iCloud Photos, email push, app updates all trigger the daily charge. A phone left in a bag with data roaming on starts a new $12 fee each time a sync lands after the last 24 hours ran out.
Vietnam FAQ
Vietnam eSIM & roaming questions
Vietnam carrier roaming costs $12 a day on AT&T and on Verizon
AT&T: $12/day, or $84 a week. Verizon: $12/day. T-Mobile: 5GB or 15GB of high-speed data included on Experience plans, then at a reduced speed, or $10 for a 1 Day pass with 2GB. Travel eSIM on a local network: from $3.49 for 1GB. On the median 5 GB plan, fixed rates run from $2.01/GB on HelloRoam to $2.60/GB on Saily. HelloRoam's 7-day unlimited plan has the lowest median of the five at $21.50 across 35 countries, against $27.50 on Holafly. Every option above routes through the same local towers in Vietnam. Difference for 7 days against AT&T on that HelloRoam plan: $62.50. Carrier rates checked June 2026; eSIM prices from the 30 Oct 2026 price check.
T-Mobile's included data in Vietnam runs at high speed until the allowance ends
For light use, yes. T-Mobile's Experience More plan includes 5GB of high-speed data abroad and Experience Beyond 15GB, then data runs at up to 256Kbps. Essentials includes texting but no data. Even at 256Kbps you stay reachable on WhatsApp and iMessage text in Vietnam, which is more than AT&T gives you without a pass. Fixed-data eSIM plans across HelloRoam, Holafly, Nomad, Airalo, and Saily run full 5G on a local network from $1.37/GB, with no daily activation trigger. Carrier rates checked June 2026; eSIM prices from the 30 Oct 2026 price check.
Vietnam roaming bills by the day, not by the gigabyte
Relying on hotel WiFi does not prevent roaming charges in Vietnam. AT&T's per-day charge fires from any background cellular contact — your phone does not need an active app, just a brief tower handshake. Per-MB billing at $2.05/MB is even more dangerous with background syncs. T-Mobile sidesteps per-day billing up to its plan's high-speed allowance, then runs at up to 256Kbps. A travel eSIM at 1GB for $3.49 gives you full 5G and locks the total cost before you board.
Coverage lists decide which provider suits a Vietnam trip with extra stops
HelloRoam is the top pick when every stop is on its list: it sells Vietnam among its 185 destinations and holds the lowest median 5 GB rate here, $2.01/GB. For a route that adds stops, check each list before the price: Airalo reaches 200+ destinations, Nomad 200 and Holafly 200+. This site states no Saily count. That breadth is worth paying for only when the itinerary is still moving. A regional plan covering several countries in one bucket beats one plan per stop. AT&T sidesteps the question by charging $12 per 24 hours in every country alike, which is simple and expensive: three countries over nine days still bills $108. Carrier rates checked June 2026; eSIM prices from the 30 Oct 2026 price check.
A one-month stay in Vietnam suits a data bucket over a day pass
For a 30-day trip at 1.5 GB/day average, total usage runs 45 GB. AT&T International Day Pass: $12/day, $120 for the month. T-Mobile International Pass: $10/day, $75. A travel eSIM on Viettel at $1.37/GB for 45 GB costs roughly $61.65. For stays over 2 weeks, also consider a local SIM purchased in Vietnam — local prepaid cards often run $10-25 for 20-50 GB at full local speeds with no international markup. Rates checked June 2026.
The three US carriers price Vietnam roaming on different terms
None of the three US carriers offer a genuinely good deal in Vietnam. AT&T: $12/day. Verizon: $12/day. T-Mobile: 5GB or 15GB of high-speed data included on its Experience plans, then up to 256Kbps, or $10 for a 1 Day pass. A travel eSIM on Viettel starts at $1.37/GB — a 7-day trip at average usage costs $14.39 versus $84 for AT&T. No carrier matches the eSIM on per-GB cost.
VPN access in Vietnam works the same on an eSIM as on roaming
VPN access in Vietnam is restricted, and the product you buy does not change that. VPNs not illegal but government blocks many VPN services; Facebook and Google generally accessible Carrier roaming and travel eSIMs both terminate on a local network, so both meet the same local filtering. Routing does differ between providers and results differ with it, but none of the five sells guaranteed access and we will not claim one does. Saily is the only provider here that bundles a VPN, which saves a separate subscription and carries no promise it works where access is restricted. Install and sign in to whatever VPN you plan to use before you fly, because the download itself may be blocked once you land.
Local Vietnam apps run on a travel eSIM without a local SIM
Most local apps in Vietnam — ride-hailing, food delivery, transit — do not require a local SIM number to function. They require only a data connection, which a travel eSIM provides at $1.37/GB on a local 5G network. Some banking and two-factor authentication apps require a local phone number for SMS verification. For those cases, keep your home SIM active alongside the eSIM — your home number handles SMS while the eSIM handles data.
One eSIM can cover a multi-country Asia route including Vietnam
Multi-country Asia eSIM plans exist and cover many combinations — Japan, South Korea, Thailand, Singapore, and others in a single data bucket. AT&T and Verizon charge $12/day in each country separately, so a 3-country trip at 3 days each costs $108. A regional Asia eSIM for the same 9 days runs $15-$40 total. Check plan coverage maps — Vietnam may be included in a regional plan, or you may need a Vietnam-specific plan plus a regional one.
A week of Vietnam carrier roaming costs $84
AT&T: $84/week (International Day Pass at $12/day). Verizon: $84/week (TravelPass). T-Mobile: 5GB or 15GB of high-speed data included on its Experience plans, then up to 256Kbps, or $50 for a week of passes (10-day pass). The cheapest eSIM for Vietnam starts at $1.37/GB on a local 5G network — better per-GB value than all three carriers.
Fact check
Vietnam travel data: correcting the record
EU roaming is free for Americans
EU roaming-within-the-EU rules apply only to SIM cards issued by EU-based carriers. AT&T and Verizon are US carriers — they charge full international day pass rates in every EU country. AT&T's International Day Pass runs $12/day in EU destinations. Verizon TravelPass is $12/day. A travel eSIM on a local network covers Vietnam for $3.49 total. Rates checked June 2026.
You need to unlock your phone to use an eSIM
eSIM installation does not require an unlocked phone in most cases. iPhones sold in the US since iPhone 14 are sold unlocked by law. iPhones XS through 13 require unlocking to add a foreign carrier eSIM, but AT&T, Verizon, and T-Mobile all offer free unlocking after your contract ends. Samsung Galaxy S20 and newer models support eSIM on both locked and unlocked variants. Check your carrier's unlock policy before your trip to Vietnam.
Roaming charges only apply to data
US carrier international plans charge separately for data, calls, and texts. AT&T's International Day Pass at $12/day includes data but charges $0.25–$1.50/minute for calls beyond the bundled allocation. Incoming voicemail retrieval can trigger per-minute roaming charges even when you make no outgoing calls. A data-only eSIM in Vietnam at $3.49 covers data and uses WhatsApp or FaceTime for voice at no additional carrier cost. Rates checked June 2026.
Our recommendation
Vietnam data cost verdict
For heavy data users in Vietnam: HelloRoam covers Vietnam on a local network and scores 9.9/10 on our rubric, the highest of the 5 providers we price. A 1GB plan costs $3.49. Unactivated plans are refundable for 180 days, and its support replies in your own language. Saily is the alternative if privacy matters most: VPN usage is restricted in Vietnam, and Saily includes NordVPN-grade encryption on every plan.
Learn more
Travel guides, Vietnam
4 guides carry the parts of a Vietnam trip this page does not price: installing the profile before departure, switching data roaming off on the home SIM, and what happens to the allowance once a fair-use policy applies. Each one reads the same rate card as this page, where AT&T bills $12 a day.
AT&T charges $12/day in Vietnam. An eSIM plan costs $27.49.
You do not need a new carrier plan for Vietnam. Buy an eSIM, scan the QR code, and your phone is online for $27.49.
Get a Vietnam eSIM