Scammers are sending fake messages to mobile phone users telling them to change their bank information.
The fake messages to O2 customers claim that payments have not gone through, so customers need to update their payment details.
But the link leads to a fake website - where criminals will steal your bank account details.
The text message to be wary of reads: "O2: Payment for your latest bill could not be processed by your bank. Please update your information".
O2 says it's an SMS phishing scam - or smishing - sent out by fraudsters in the hope that customers will click on a link and enter personal details.
What to do if you get a suspicious text:
- If you receive one of the text messages, you can make O2 aware by forwarding it to 7726.
- You can also report it to Action Fraud or email the Government's new phishing report service: firstname.lastname@example.org
What are the signs a message may be fake?
O2 says it will never email, text or call customers and ask for a one-time code, password or other security information set up on your O2 account.
It says the messages can look very convincing and can mimic genuine messages sent by organisations you already deal with.
The signs a message might be fake include:
- Spelling mistakes
- A generic 'dear customer' header
- Asking you to provide sensitive personal or financial information, passwords, or to make transactions by following a link in the message
- Suspect links or a name in the header with extra letters, numbers or substitutions. For example, a phishing scam trying to imitate O2 might replace the letter 'O' with the number zero
- Being asked to call a certain number you don’t recognise. In this case, call your bank on a number that you trust, like the one on the back of your card, to check the message is authentic
- Using an urgent tone and telling you to act now.