China, Hong Kong and Macao: Three-Stop Connectivity Checklist

For mainland China, Hong Kong, and Macao, verify all three destinations and the exact phone before buying. The current co:sim Greater China plan lists China Unicom (5G) and China Telecom (4G) on the mainland, csl and SmarTone (5G) in Hong Kong, and CTM (4G) in Macao. Those are catalog partners, not guarantees of signal or app access at every stop; save border and hotel details offline.

#What should a three-stop connectivity checklist include?

List each stop and the return route. Match mainland China to the currently listed China Unicom or China Telecom options, Hong Kong to csl or SmarTone, and Macao to CTM on the specific regional package. A mainland-only plan does not establish service after either border. If you use home roaming instead, compare its partner and charges in each place. Before a rail or ferry transfer, save the next ticket, address, and contact; a phone may need time to register on a different partner after crossing.

List the apps needed immediately after each crossing: maps, hotel check-in, payment, rail or ferry tickets, and account verification. In mainland China, access to a particular app can depend on local restrictions, the app itself, and how the connection is routed. A travel eSIM does not by itself bypass those restrictions or guarantee access. Check essential apps with the actual connection when possible, and save addresses, tickets, and a hotel contact through an offline channel. A data-only line also cannot receive ordinary SMS codes for your existing number.

Check the handset's exact sales-region model, EID, and Add eSIM control against co:sim's supported-device guidance. Apple's current setup guide says: “In China mainland, only iPhone 18 Pro, iPhone 18 Pro Max, iPhone 17e, and iPhone Air support eSIM.” It also notes that certain Hong Kong and Macao models use two nano-SIM cards. Check the actual model and the selected provider's activation rules before travel; installation abroad may be required by those rules, but crossing into Hong Kong cannot add missing eSIM hardware.

Photo: Dimitry B, CC BY.

#Should you use one regional eSIM or separate plans?

If most of the trip is in one place, compare that destination's own plan too. The Hong Kong data-only page and Macao data-only page let you inspect narrower options, while the regional page is the right starting point for a genuine three-stop route. The answer may be a combination: one data eSIM for travel plus a home number retained for calls or SMS. Check dual-SIM controls and roaming charges before leaving the home line active.

#What changes when you cross from the mainland to Hong Kong or Macao?

Treat each crossing as a network-registration event: a mainland connection using China Unicom or China Telecom may hand off to csl or SmarTone in Hong Kong, then to CTM in Macao, depending on the exact plan and available signal. Stop somewhere safe, wait for registration, and test a simple webpage before opening a booking app. If signal appears without data, check the chosen data line, the plan's roaming setting, APN, and destination list. Do not delete the profile as an initial fix; keep the QR email and support instructions offline.

The administrative details also change by route and traveler. Hong Kong's Office of the Communications Authority is an official source for local telecom information, and the Macao Government Tourism Office provides destination guidance. China Mobile's official site is a mainland operator source. For border entry documents, visas, and identity rules, consult the relevant government authority for your nationality and itinerary; a mobile-data article cannot generalize these requirements. Save the needed documents and transport confirmations where they can be opened offline.

Photo: Pat Cullen, CC BY.

#How should you set up your phone before the first stop?

1. Confirm the exact model, sales region, unlock status, EID, and Add eSIM menu. Check Apple and provider activation rules before entering mainland China.
2. Check that the plan explicitly lists mainland China, Hong Kong, and Macao. Read network partners, data allowance, validity, billing-start rule, and install deadline.
3. Install over dependable Wi-Fi at a permitted location before travel. Save the QR email, plan instructions, tickets, and addresses offline.
4. Label the lines on the phone. Choose the travel line for mobile data and follow the plan's roaming setting instructions. Keep the home line only for the functions and cost you have checked.
5. After each crossing, wait for network registration and test a simple webpage. If needed, review line selection and APN before contacting support over Wi-Fi.

The QR code from co:sim arrives by email after checkout, but a QR code cannot overcome missing eSIM hardware or a market-specific installation restriction. Verify compatibility before buying. If a phone cannot use a travel eSIM, compare physical SIM or your home carrier's roaming. Carry power and offline directions so a brief registration gap does not strand you at a station or ferry terminal.

Match the live destination list and the exact phone to the itinerary before buying. Save the essentials offline and compare regional, single-destination, and roaming terms for each stop.

Browse Greater China data-only plans

#FAQ

#Will a single eSIM work in mainland China, Hong Kong and Macao?

Only if the chosen package lists all three destinations and the phone can install it. The current co:sim regional page names mainland China Unicom (5G) and China Telecom (4G), Hong Kong csl and SmarTone (5G), and Macao CTM (4G); verify the exact plan again before checkout. A “China” label alone is insufficient. At each border the phone must register with an available partner, which may interrupt data even when the next territory is included. Check the handset's EID and eSIM menu, keep tickets and hotel directions offline, and retain a numbered line for ordinary SMS codes. Partner listings describe networks, not guaranteed coverage or access to every app; test the services you actually need before depending on them.

Before a ferry or train crossing, save the next station exit and hotel address in case registration takes longer than expected.

#Can I install a travel eSIM after arriving in mainland China?

Do not assume you can. Apple states that in China mainland only iPhone 18 Pro, iPhone 18 Pro Max, iPhone 17e, and iPhone Air support eSIM. A similarly named phone sold elsewhere may have different SIM hardware, and a provider may impose its own activation conditions. Before purchase, check the exact model, EID, Add eSIM menu, unlock status, and the selected plan's installation rules against co:sim's device guidance. If the rules require installation before entering the mainland, complete the download over reliable Wi-Fi where permitted; storing the QR image is not installation. Arrange a physical SIM or suitable home roaming if compatibility remains uncertain. Moving to Hong Kong cannot make an unsupported phone eSIM-capable.

If the provider requires installation before entry, confirm that the profile appears in phone settings while reliable Wi-Fi is still available.

#Do I need a separate phone number for this three-stop trip?

A data-only eSIM supplies mobile internet, not a mainland Chinese, Hong Kong, or Macao telephone number or standard SMS. Internet messaging and calling can work when the data connection and app are available, but bank or airline codes sent by ordinary SMS still go to the numbered line that owns them. On a compatible dual-SIM phone, you may keep a home number active and select a regional eSIM for data; verify your home carrier's roaming, call, and text costs before doing so. co:sim plans are data-only, so check a local numbered SIM or home roaming if a conventional local number is essential. Also keep hotel and transport contacts offline, because a border crossing or network switch may briefly interrupt mobile data. The right combination depends on your bookings and the apps you must use.