Huge roaming bill?
How to check charges and dispute it in Hong Kong
Back from a trip to a roaming bill in the thousands? This page explains what to do now, where to check charges, what your carrier should warn you about, and how to complain.
Last updated: 2026-10-04
Quick answer: do these 3 things now
- 1. Tell your carrier you dispute it: ask it to hold the disputed amount and stop autopay for it. Keep paying the undisputed part.
- 2. Ask for an itemised bill: daily data usage, connection times and overseas networks used.
- 3. Complain in writing: ask whether it sent the usage alerts in its bill-shock measures. If stuck, call OFCA on 2180 9521 about CCSS mediation.
- Free to use
- Independent, not linked to any carrier
- Information from OFCA
Why roaming bills shoot up: 4 common causes
Day pass not activated
You thought you’d added a day pass, but were charged standard pay-per-use rates.
Background data
Photo backups, app updates and auto-playing videos. OFCA suggests turning off auto-updates and autoplay before you travel.
Cruise or in-flight networks
Sea and in-flight networks may not be covered by normal day passes – check with your carrier before you go.
Roaming calls and voicemail
Data day passes usually don’t cover calls. Answering calls abroad, or even diverting to voicemail, may be charged.
OFCA warns: following instructions or tapping links in welcome or promotional texts at your destination may switch on mobile data.
Where to check roaming charges (csl, CMHK, SmarTone, 3HK, Club Sim)
Roaming prices change often – check each carrier’s official website for the latest rates.
| Carrier | Official website |
|---|---|
| csl / 1O1O | Visit website → |
| China Mobile Hong Kong (CMHK) | Visit website → |
| SmarTone | Visit website → |
| 3HK | Visit website → |
| Club Sim | Visit website → |
On the carrier’s page, check these 5 things:
- Which price zone is your destination in? Prices can differ a lot between countries.
- Is the day pass automatic, or do you add it? Using data without one may mean pay-per-use rates.
- What happens after full-speed data runs out? Slower speed, cut off, or extra charges?
- Are calls, texts and voicemail included?
- Are there usage alerts and limits? When will you get a text, and will roaming pause?
Screenshot the price page and plan terms before you travel. If your bill doesn’t match, those screenshots are your evidence.
Does your carrier warn you? Bill-shock measures
OFCA publishes mobile operators’ bill-shock prevention measures. They are voluntary and differ between operators. Common ones include:
- A text alert when usage reaches a set level
- Pausing mobile data after a limit is passed
- Some offer confirm-before-use: a text asks you to confirm before roaming starts
See OFCA: operators’ bill-shock prevention measures.
Use this in your complaint: if your operator has published such measures but you never got an alert, or roaming wasn’t paused, ask it to explain and request a waiver on that basis.
Roaming bill dispute letter template
Replace the [ ] parts with your details and send it by email or online form to your carrier’s customer service or complaints team.
Subject: Roaming bill dispute – request for usage records and a hold on charges (Account no. [number]) To the Customer Service / Complaints Department, [Carrier name]: I am [name], account no. [number], mobile number [number]. From [date] to [date] I was in [destination]. My bill dated [date] includes roaming charges of [amount], which I dispute. Please: 1. Provide detailed records for that period: daily data usage, connection times and the overseas networks used; 2. Confirm whether the roaming day pass I added, [plan name], was activated; 3. Provide records of any usage alert texts you sent (date, time and content); 4. Explain whether you paused data roaming when usage passed the limit, as your published measures state; 5. Hold the disputed amount, and stop autopay for it, while you investigate. I will continue to pay the undisputed charges. Please reply in writing within a reasonable time and [waive / refund] the disputed amount. Attachments: [copy of bill, travel proof, day pass confirmation text, screenshot of price page] [Name] [Phone number] [Date]
How to dispute a roaming bill: 3 steps
- 1
Complain to your carrier in writing
Phone calls are hard to prove. Use email or an online form with your account number, bill date and amount, whether you got alerts, whether your day pass was active, and what you want. Keep the reference number and all screenshots.
- 2
Get detailed usage records and check them
Compare them with your trip: was data used before you left or after you came back? Did you connect to a cruise or in-flight network?
- 3
Stuck? Apply to the Customer Complaint Settlement Scheme (CCSS)
For billing disputes that have reached a deadlock. First call OFCA on 2180 9521 to check eligibility; eligible cases are referred to the scheme agent. Accepted cases pay a non-refundable HK$50 mediation fee. OFCA CCSS details
3 settings before you fly
iPhone
- Settings → Mobile Service (or Cellular) → Mobile Data Options
- Turn off Data Roaming (turn on only when your day pass is active)
- Turn off Background App Refresh and pause iCloud Photos
Android (menus vary by brand)
- Settings → Connections or Network & internet → Mobile network
- Turn off Data roaming
- Pause Google Photos backup; update apps over Wi-Fi only
Call your carrier first
- Confirm your day pass is active (wait for the text)
- If not needed, ask to suspend roaming, or roaming calls and voicemail
Roaming bill FAQs
I turned off data roaming. Why was I charged for calls?
Data roaming and call roaming are separate. Answering calls abroad is usually charged, and calls diverted to voicemail may be too – check with your carrier before you travel.
If I don’t pay the disputed amount, will my service be cut?
It could be, depending on your carrier’s terms. Pay the undisputed part, ask the carrier in writing to hold the disputed amount, and keep a record of its reply.
Must my carrier send usage alerts?
The bill-shock measures published by OFCA are voluntary and differ between operators. If your operator has published a measure but you never got the alert, ask it to explain.
Who can help with a roaming bill dispute?
Complain to your carrier in writing first. If the dispute reaches a deadlock, call OFCA on 2180 9521 to see whether you can apply to the Customer Complaint Settlement Scheme (CCSS); accepted cases pay a non-refundable HK$50 mediation fee.
Contract questions? See our telecom contract renewal guide.
References
Related guides
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This page is general information only and is not legal advice. RightlyHK is not affiliated with any carrier or government body. Roaming prices change often – check your carrier’s official website.