• On typical consumer plans, China Mobile’s monthly alert tells you how much data you’ve used. It usually does not include your cash balance. Checking typically takes only a few seconds once you know how.
• Every Chinese prepaid number is subject to a recycling mechanism. Many expats only discover this after discarding an old SIM without considering what was still bound to it.
• All three major carriers currently offer a service that keeps old numbers protected for roughly 5–10 RMB a month.
• If you are a China Mobile user who travels, there is an app that can let your Chinese number receive calls and SMS over WiFi abroad, provided you set it up in advance.

Each billing cycle, many China Mobile users receive a recurring data-usage message. Data running low, x amount of gigabytes remaining. In practice, this message typically does not include how much money is left in the account.

Checking usually takes only seconds with the correct SMS command.

How to Check Your Balance in Seconds

The simplest method works on virtually any standard phone and requires no app, no login, and no Chinese. Send a text message to your carrier’s service number with the relevant command.

In normal conditions, the reply arrives within seconds.

For China Mobile users who want to check data usage on demand, instead of relying on the monthly SMS many plans, send CXLL to 10086. The reply shows current data consumption and remaining allowance for the billing period.

Commands may vary by province and plan, if a command returns no result, the China Mobile app or WeChat mini-program are generally reliable alternatives across regions and devices.

Your Old SIM Card Is Probably Still Bound to Your Accounts

Many expats in China have (probably) had more than one SIM card. The first one from arrival, possibly another when switching carriers or cities, maybe one picked up for a specific trip.

What happens to the old numbers is something many people do not think much about at the time.

Every Chinese prepaid number is subject to a recycling mechanism.

When the balance reaches zero and stays there, the account enters suspension. After an inactive period, commonly reported as approximately 90 days, though this varies by carrier and plan, the number is formally deregistered and made available for reassignment to a new user.

One key reason this matters is that a Chinese phone number is rarely just a number. For many expats, it is the primary binding point for WeChat, Alipay, bank accounts, and various government service platforms.

In documented cases, those bindings have not dissolved when a number went inactive, the account stayed linked to that number until the user actively changed it.

What happens on WeChat

For WeChat specifically, a documented mechanism exists: if a new user registers on a recycled number and confirms it is recycled, the number is automatically unbound from the previous owner’s account.

For other platforms including Alipay and banking apps, the behaviour when a number is recycled has not been confirmed in official documentation.

Users should update their bindings proactively, instead of assuming that inaction will automatically keep those accounts protected.

The practical question for anyone who has discarded a SIM without formally cancelling it is whether that number is still bound to active accounts, and, if so, whether those bindings have been moved to a current number before the old one is recycled and reassigned.

We will examine this topic in more detail in the next article.

The 5 RMB Service That Keeps Your Number Safe

All three major carriers offer a service called 停机保号, service suspension with number preservation. Calls and data are suspended, but the number is held against recycling. Based on available user experience, the service continues as long as the monthly fee is paid.

Reported monthly fees are approximately 5 to 10 RMB depending on the carrier:

These are general fees and will vary by plan, province, or registration type. Confirm the current fee with your carrier before activating.

How to activate it

The service is available to foreign passport holders though availability may vary by carrier or branch. Setting it up typically requires calling the carrier’s customer service line or visiting a store in person with your passport:

Travelling? Set This Up Before You Leave China

China Mobile users have an additional option worth setting up before any international departure.

The 无忧行 app (Wuyouxing), published by China Mobile International (中国移动国际有限公司), offers a function called 号码托管, number hosting. Once activated, your China Mobile number receives incoming calls and SMS messages through the app over any WiFi or data connection, without a physical SIM card inserted or a roaming plan active. Receiving incoming calls and SMS, including verification codes, is free (at the time of writing). Making outbound calls is supported but charged at standard domestic rates or via a separately purchased voice package.

Users report success receiving SMS verification codes through the app for most major Chinese platforms, though delivery reliability may vary by platform and service.

How to set it up

1. Search for 无忧行 in the Apple App Store or Android app stores, published by China Mobile International (中国移动国际有限公司). Download and open it while your SIM is still active.

• Log in with your China Mobile number. A verification code is sent by SMS to confirm identity. Complete this step before touching your SIM settings.

• In your phone’s network settings, switch from 5G or VoLTE to 4G. The number hosting function does not work on 5G or with VoLTE enabled.

• Deactivate or physically remove your China Mobile SIM card (if the physical SIM is active and connected, the network routes calls and SMS directly to the SIM rather than through the app).

• In the app, navigate to 电话/消息 (Calls/Messages) → 号码托管 (Number Hosting) and complete the activation steps.

• Once active, incoming calls and SMS to your China Mobile number will appear in the app over any internet connection.

Important notes:

• The app and its interface are in Chinese only
• Outbound SMS is not supported, only outbound calls (charged)
• If the physical SIM is switched back on and connects to a network, 托管 deactivates automatically. It can be re-enabled in the app after switching the SIM back off
• Setting up 号码托管 while already abroad is technically possible if your SIM has roaming enabled, but the process is more complex and not recommended. Set it up before leaving China

China Unicom and China Telecom users

China Unicom and China Telecom have their own carrier apps, 联通手机营业厅 and 天翼生活 respectively. Whether these apps offer comparable number hosting functionality for receiving SMS abroad has not been confirmed. China Unicom and China Telecom users should contact their carrier directly before travel to determine what options exist.

A Separate Conversation

The commands above and the number preservation service are practical steps that take minutes to set up. What they do not address is the deeper question, which services are currently bound to a Chinese phone number, what options exist to find out, and what happens if a number has already been recycled.

We’ll cover that in the next article.

Related article: Why Your Name Doesn’t Match Across Chinese Systems, and What to Do About It

Why Your Name Doesn’t Match Across Chinese Systems, and What to Do About It – TropicalHainan.com

Your name exists in five different systems in China. Zero automated checks and they don’t talk to each other. Here’s what happens when they disagree …

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