Use an official operator route and keep your passport ready
A Cambodian government visitor page says prepaid SIMs and eSIMs are available at international airports and official operator shops, with a valid passport required for registration. It names Smart, cellcard and Metfone as major networks. For a physical local line, that makes an official shop or marked airport counter a practical first stop: staff can register the passport details and show whether the card attaches to a network before you leave. Avoid treating a sealed card from an unverified seller as already usable, especially if you need an SMS-capable Cambodian number for bookings.
Cellcard's own purchase page lists stores and service points for physical SIMs and describes a separate eSIM purchase through its app. Smart offers a website, SmartNas app and Smart Shop route for its eSIM. Those paths all lead to a Cambodian operator product, but their identity and payment steps differ. If you only need mobile data for a brief stay, compare the time needed to complete registration with an already arranged roaming plan. If you need a local number for ordinary calls or SMS, make sure the selected product includes those services rather than assuming that every eSIM does.
Smart's app has a remote identity check
Smart says a new eSIM can be bought through SmartNas, its website or a Smart Shop. The operator asks for an eSIM-compatible handset, Wi-Fi and either a national ID or valid passport. Its app instructions for a new customer include scanning the document, taking a face scan, selecting a number and plan, adding an email address and completing payment before activation. This is a more detailed route than a vague promise of instant eSIM service: it still needs successful identity verification and a working internet connection while the profile is delivered.
Prepare the phone before beginning the SmartNas flow. Check it is unlocked, confirm eSIM support for the exact model and keep Wi-Fi connected while the purchase completes; Smart specifically warns against closing the app or disconnecting during payment. A second device can be useful for showing a QR code or instructions, but follow the delivery method actually offered in the completed order. The page also advertises discounts on special phone numbers. Those are a separate promotion, not the ordinary data-plan price, so compare the plan allowance and validity in the final checkout instead of using the promotional number price as a guide.
Cellcard links an eSIM to the eArrival flow
Cellcard announced in June 2026 that visitors could purchase and activate one of its 5G-ready eSIMs through the Cambodia eArrival app. The operator says the app covers arrival information as well as the mobile purchase. Treat this as cellcard's description of its own channel: confirm that the eSIM option appears for your device and entry route before you rely on it as your only connection after landing. The announcement does not by itself establish a fixed plan price, a guaranteed activation time or 5G reception at every destination.
Cellcard also offers app-based eSIM purchase outside the eArrival route and physical cards at its stores and service points. Its general eSIM page says some listed plans waive an eSIM purchase fee through digital channels, but it explicitly says the number and plan fees are separate. That distinction matters when comparing the final cost with a physical SIM or a travel plan. Read the plan's data, voice and expiry terms at the actual checkout, retain the confirmation, and test service before leaving a place with Wi-Fi.
Use the regulator's 5G locations as a planning clue
The Telecommunication Regulator of Cambodia says commercial 5G launched in January 2026 and reports rollout by Smart Axiata, CamGSM, which operates cellcard, and Viettel (Cambodia), which operates Metfone. Its June 2026 release lists 5G base-station work in Phnom Penh and specific provincial capitals. Smart's list includes Siem Reap, Battambang and Preah Sihanouk; Viettel's list also includes places such as Ratanak Kiri and Stung Treng. A listed base station is evidence of rollout activity in an area, not a promise that every street, temple site or guesthouse gets a reliable 5G signal.
The regulator says the operators are still expanding 4G and 5G and that it intends to monitor 4G quality. That is a reason to check a plan's 4G performance and the current operator map as carefully as its 5G label. For a route from Phnom Penh to Siem Reap and then a rural province, download directions, accommodation contacts and key tickets while you have a stable connection. If work depends on mobile data, compare the actual networks used by any two plans; two eSIM profiles are not automatically two separate radio networks.
Set the right profile for a cross-border itinerary
Cambodia's government visitor page places the country beside Thailand, Laos and Vietnam and identifies +855 as its calling code. A local Cambodian SIM should not be presumed to include data once you cross one of those borders; inspect the operator's roaming terms or the destination list of any regional plan before leaving. Keep your home number enabled if it must receive ordinary bank or booking SMS, while directing mobile data to the intended travel line. At a border, a phone may attach to an adjacent network before or after immigration, so check the displayed operator and data settings rather than relying on a country name in a plan advertisement.
The eArrival route can reduce setup work if it appears for your trip, but it is still sensible to save the arrival confirmation and hotel address offline. Cellcard's app supports top-ups and account management, while Smart's app is the purchase channel described for its new eSIM. Those functions need a connection and may require the registered number or email, so save the purchase details before a long coach journey. A Cambodian local number can help with ordinary calls, while a data-only plan is appropriate when internet-based maps and messages are enough.
Keep the short emergency codes accessible
Cambodia's telecom regulator lists 117 for police, 118 for fire and 119 for an ambulance. These are telephone short codes, so do not assume that a data-only eSIM can dial them simply because it opens websites. Keep a voice-capable line or another dependable calling option, and know which SIM your dual-line phone selects for outgoing calls. The regulator also lists 1205 for its telecommunication device identity registration service, but its short-code list alone does not establish a visitor IMEI-registration deadline; ask the relevant authority if a device-status issue arises.
Before flying, check your phone's lock status and eSIM support, download an offline map for the first transfer and save the purchase instructions. If using an operator app, carry the passport that will be scanned and start the process with stable Wi-Fi. On arrival, test a map, a message and any local voice allowance before you leave the airport or official outlet. If an app-based purchase fails, the government visitor page identifies airport counters and official operator shops as alternatives for a registered card.
Networks our Cambodia plans use
These are the operators named on our plans for Cambodia, taken from the plan data, so the list follows the catalogue.
- CamGSM (Cellcard)4G
- Cellcard4G
- Metfone4G
- Smart4G
- Viettel4G
- Viettel(Metfone)LTE