A foreign number rang once and hung up: should you call back?

How the one ring turns into a charge

The FCC describes the scheme like this: an automatic dialler calls thousands of numbers, lets each one ring once or twice and hangs up, often in the middle of the night, so you wake up to a missed call. If you call back, you can be connected to a premium-rate service abroad, and the cost appears on your bill as a premium service or an international call.

The FTC adds that the numbers are chosen to look familiar. Some country codes have three digits, like an area code, which is how a number starting with 232, Sierra Leone, or 809, the Dominican Republic, can pass for a domestic call in the US. Spoofing can disguise the number further, so even one that looks authentic deserves a second look.

Why travellers are an easy target

At home, a missed call from another country is odd. On a trip it is normal: the hotel, the apartment host, the transfer driver or the tour company may all call from local numbers you have never seen. That is exactly the instinct the scam relies on.

Roaming adds a second layer. Inside the EU, roam like at home covers ordinary calls, but the EU roaming regulation says its price rules apply only to the connection, not to the part of the tariff charged for value-added services such as premium-rate numbers. That is why your operator has to send you a free automatic message when you arrive in another EU country, warning about higher charges for those services and linking to a page with details. Outside the EU, even a normal call back can be expensive, as our guide on avoiding roaming charges outside the EU explains.

How to check before calling back

• Wait. The FCC's advice is that if someone really needs you, they will leave a voicemail or try again.
• Look at the country code. If it belongs to a country you have no connection with, do not call it.
• Save the numbers of your hotel, host and driver in your contacts before the trip, so a genuine call shows up with a name.
• Reply through the channel you already use with them, such as the booking app or a chat, instead of dialling an unknown number.
• If you never make international calls from your home line, the FCC suggests asking your operator to block outgoing international calls.

Most travel companies now confirm things by message, so a single ring with no text and no voicemail is rarely something you need to answer.

Phone settings that help, and one that does not abroad

On iPhone, go to Settings, Apps, Phone and choose an option under Screen Unknown Callers: Never, Ask Reason for Calling or Silence. Silence sends calls from unsaved numbers to voicemail and still lists them in Recents. There is a catch for travellers: Apple says that when you are roaming, calls are not screened, whatever your settings. The Unknown Callers option under Call Filtering in the same menu still moves missed calls and voicemails from unknown numbers into a separate list.

On Android with Google's Phone app, open More options, Settings, Caller ID & spam and turn on Filter spam calls. Google says you will not get missed call or voicemail notifications for filtered calls, but they stay in your call history. On phones with automatic Call Screen, spam blocking is one of the Call Screen options instead.

If you already called back

Hang up as soon as you realise, and keep a note of the number and the time. Check your bill or your operator's app over the next few days for premium or international charges. The FTC and the FCC both say to try to resolve the charges with your operator first, and to file a complaint if that does not work. Our guide on what to do about an unexpected roaming bill covers how to dispute a charge.

The call came to your usual number, not to a travel eSIM. A data-only eSIM has no number, so it does not receive calls of any kind. If you want fewer surprises, you can keep your home line on for calls and texts you trust and do everything else over data, as we explain in how to call home with a data-only eSIM.