UK phone number search

A text from a number you don't recognise: what to do

By the StoryCheck team · 6 min read · Published 29 September 2026

A text from an unknown number in the UK is usually one of five things: a payment or delivery link, a friendly 'wrong number' opener, a relative claiming to have a new phone, a message pretending to be an organisation, or a genuine text from a business or tradesperson. Do not reply or tap a link until you know which, check the sender through a number you already trust, and forward anything suspicious to 7726, which is free.

What kinds of text arrive from unknown numbers?

The courier, family, HMRC and job versions each have their own guide: Royal Mail texts, Hi Mum messages, HMRC scam calls and texts and job offer texts.

Why shouldn't you reply, even to say stop?

Because a reply is what the sender wants. Ofcom's advice is not to reply to a text from an unknown sender, even to opt out, because replying confirms your number is active. The 'wrong number' opener works on exactly that: a polite correction starts a conversation, and the conversation can turn, sometimes weeks later, into an investment pitch or a request for money. Opening the message does no harm. Tapping the link, replying, installing something or entering details on a linked page is where the harm starts.

How can a scam text land in your bank's own thread?

Scammers can fake the name or number a text appears to come from, so a fake message can sit in the same thread as genuine texts from your bank, a trick the Home Office's Stop! Think Fraud campaign warns about. Ofcom's rules finalised in July 2026 require mobile networks, and the firms that carry business texts, to check that a sender name really belongs to the business using it, to block known scam links and numbers, and to limit how many texts a pay-as-you-go SIM can send. That should cut the volume, but a sender name on its own will never be proof.

Genuine organisations do text. HMRC, for example, now sends some branded messages that show HM Revenue and Customs as the sender with its logo and verified sender details, and it still says it will never ask for personal or financial information by text. The test is not who the text claims to be from but what it asks you to do.

How do you check who really sent it?

1. 1

   Use nothing from the message

   Ignore the link and any number in the text. Both lead wherever the sender chose.

2. 2

   Go to the source yourself

   For an organisation, use its app, type its web address yourself or find its number on GOV.UK. For a person, ring the number you already have saved for them.

3. 3

   Look up an unknown mobile

   If the text comes from a number you cannot place, search it in quotation marks, see whether it has a WhatsApp profile, and run a private lookup for its line type, network and any linked profiles.

4. 4

   Decide on the evidence

   A virtual number claiming to be your bank, or a brand new number claiming to be your son, is a contradiction. Treat it as a scam until you have proved otherwise.

A private number lookup takes about 60 seconds and the sender is never told. If the unknown number is messaging you on WhatsApp rather than by text, our WhatsApp guide covers what the app itself shows.

How do you report a scam text in the UK?

1. Forward the text to 7726, which is free. On an iPhone, press and hold the message, tap More, then the forward arrow; on Android, press and hold it and tap Forward.
2. Report it in your messaging app as well, with Report Spam on an iPhone or Block and then Report spam in Google Messages. Ofcom suggests doing both where you can.
3. WhatsApp messages cannot usually be forwarded to 7726, so block and report those inside WhatsApp.
4. Forward texts pretending to be HMRC to 60599 as well, and send suspicious emails to report@phishing.gov.uk.
5. Report unwanted marketing texts to the ICO, which takes complaints about spam texts and nuisance calls.
6. If you have lost money or been hacked, ring your bank on 159 and report it to Report Fraud on 0300 123 2040 (England, Wales and Northern Ireland) or to Police Scotland on 101.

What if you have already replied or tapped the link?

• You replied: stop responding, block the number and expect more messages, because your number is now confirmed as active.
• You tapped the link but entered nothing: close the page and do not install anything it offers.
• You entered card or bank details: ring your bank on 159 straight away so it can stop the card and check for payments you did not make.
• You installed something: contact your mobile provider, and avoid using banking apps on that phone until you know it is safe.
• You feel shaken by it: Citizens Advice offers free, confidential support on 0808 223 1133, and in Scotland Advice Direct Scotland is on 0808 164 6000.