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uk Personal safety & immediate danger

What to do if…
you see a stranger checking door numbers or mailboxes in your building

Produced and maintained by PanicStation.org Published: Last reviewed: Editorial policy UK guide

Short answer

Do not confront them in the corridor. Get behind a locked door or into a staffed public area, alert the concierge, managing agent, or landlord, and call 999 if you think a crime is happening now or anyone is in immediate danger.

Do not do these things

  • Don’t confront them, follow them, or try to block their way.
  • Don’t open your flat door to speak to them.
  • Don’t buzz them in, hold the communal door, or prop doors open for them.
  • Don’t tell them your flat number, who lives where, or who is or is not home.
  • Don’t approach to check ID if you feel unsure or unsafe.
  • Don’t ask other residents to gather in the corridor to challenge them.

What to do now

  1. Create distance first. Step back inside your flat and lock the door, or move calmly to a staffed public area such as a lobby or concierge desk.
  2. Secure the communal entry behind you. If you have just entered, check that the communal door closes and latches. Do not allow tailgating.
  3. Ask building staff to verify. Contact the concierge, managing agent, landlord, or building security and ask them to check whether a visitor, contractor, delivery, or appointment is expected.
  4. Give facts, not guesses. Tell staff:
    • where the person is, such as the floor, corridor, lift area, or mailboxes;
    • what they are doing, such as checking door numbers, reading mailboxes, pressing buzzers, or looking for a specific flat;
    • a brief description, such as clothing, approximate age, bags, tools, or vehicle if safely visible;
    • whether they are trying handles, forcing doors or mailboxes, threatening anyone, or refusing to leave.
  5. Call police if the risk is immediate.
    • Call 999 if you think a crime is happening now, someone is in immediate danger, the person is forcing entry, trying door handles, threatening anyone, carrying a weapon, or the situation may become violent.
    • Call 101, or report online through Police.uk or your local police force, if it is suspicious but not an emergency.
  6. If they knock, keep the barrier. Do not open the door. If you choose to respond, speak through the door and say: “I can’t help. Please contact the resident you’re looking for or the building management.” Then stop engaging.
  7. Record details safely. From behind a closed door or another safe place, write down the time, location, what happened, and who you contacted. Only take a photo or video if you can do it without approaching, being seen, or escalating the situation.
  8. Ask for a same-day building notice. Ask management to remind residents not to buzz in strangers, not to hold communal doors open, and to report tailgating, mailbox tampering, or door-handle trying.

What can wait

  • You do not need to decide whether they were definitely casing flats or simply lost.
  • You do not need to investigate, patrol corridors, or organise residents to confront them.
  • You do not need to decide about cameras, new locks, or building-wide changes in the moment.
  • You do not need to write a perfect report before asking staff or police for help.

Important reassurance

It is common to freeze, doubt yourself, or worry about overreacting. You are allowed to prioritise distance, a locked door, and help from building staff or police without proving the person’s intent.

Scope note

These are first steps only to stabilise the situation and reduce immediate risk. Later decisions about building security, tenancy issues, repeated incidents, or police follow-up may need specialist help.

Important note

This guide is general information only. It is not legal, medical, financial, therapeutic, security, or other professional advice.

Additional Resources

Closely connected guides that may be useful during the same situation or its immediate aftermath.

About this guide

This guide was produced and is maintained by PanicStation.org using its published editorial process. Official and specialist sources are checked where relevant, and AI-assisted tools may be used for drafting, organisation, and consistency checks. The site operator remains responsible for publication, revision, and removal decisions.

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