Short answer: when one person or vehicle follows another through a controlled entrance without being verified separately, gate security should keep the access point safe, apply the site’s agreed challenge and denial procedure, call for support when needed, and record facts. The officer should not assume that the first authorised user has vouched for everyone behind them, but should also avoid an unsafe confrontation or blocking an emergency route.
Tailgating can happen at a pedestrian turnstile, reception door, warehouse entrance or vehicle gate. Sometimes it is deliberate; sometimes it is habit, courtesy, congestion or a driver following the vehicle ahead. The response should be proportionate to what is observed and based on the assignment instructions, not on guesswork about someone’s intentions.
The site owner or occupier controls the access policy. Security can verify credentials, keep the record and escalate within an agreed brief. Managers remain responsible for deciding who may enter, what exceptions apply and how the physical and electronic systems should operate.
Define tailgating in the site instructions
A useful instruction should distinguish at least three situations:
- Pedestrian tailgating: a person passes through a controlled door, gate or turnstile using another person’s access event.
- Vehicle tailgating: a second vehicle enters before the barrier, gate or verification process has reset.
- Authorised group access: a pre-approved party is admitted under a named sponsor or documented group procedure.
Without that distinction, staff may treat a breach as normal courtesy while an officer treats it as unauthorised entry. The rule should be communicated to employees, contractors, drivers and visitors before security is expected to enforce it.
The National Protective Security Authority’s guidance on perimeters and checkpoints identifies tailgating as one way people may attempt unauthorised access. It recommends considering access control, procedural controls, surveillance, guarding, emergency access and contingency arrangements together rather than relying on one device or one officer.
Agree what the officer may do
The assignment instructions should say whether the officer may ask the person to present a pass, return to reception, wait in a safe holding position or contact a sponsor. They should also state when the officer closes the access point, calls a supervisor, requests another officer or contacts the police.
“Challenge everyone” is not a complete procedure. It does not explain the safe distance, wording, available support, response to refusal, treatment of known senior staff, or the priority during a fire alarm or medical emergency.
The officer should not invent sanctions, seize a personal phone, retain identity documents without authority or physically block a moving vehicle. If someone refuses to stop, the instruction should provide a safe escalation route rather than encouraging pursuit into an unassessed area.
Use a calm, observable response
A practical response sequence is:
- Keep the access point safe. Do not step into a vehicle path, trap a person in a door or create a crowd around the checkpoint.
- State the rule clearly. Explain that each person or vehicle must be verified separately under the site procedure.
- Request the approved credential. Ask for the pass, booking, registration, sponsor or other evidence listed in the instruction.
- Move the check to the agreed position. Keep reception, a pedestrian route or a vehicle holding area clear while the verification takes place.
- Escalate exceptions. Use the named contact or supervisor rather than accepting “they know me” or “I am with them” as authority.
- Record the outcome. Note whether access was verified, refused, abandoned or authorised by a named person.
This approach separates observation from accusation. The officer can apply the access rule without publicly labelling someone dishonest or dangerous.
Do not let courtesy replace verification
Employees often hold a door for a colleague, contractor or delivery worker. A driver may wave another vehicle through because they appear to be travelling together. Those gestures may be well intended, but they transfer an access decision to someone who may not know the current authorisation.
The site should teach users not to lend passes, allow unknown people to follow them, or challenge suspected tailgating themselves unless that is part of their role. They should close the access point normally and notify security. Posters and induction material should support the same rule the officer is applying.
Where a visitor is expected to remain with a sponsor, the procedure should explain whether the sponsor may admit the person or whether reception must verify them first. Our guide to visitor access at shared commercial premises covers the sponsor’s role in more detail.
Separate pedestrians from vehicle movements
Vehicle tailgating should not be solved by placing an officer between vehicles or closing a barrier onto a moving vehicle. The gate design, holding area, intercom, barrier timing and verification process should allow a second driver to stop safely without obstructing a public road or pedestrian crossing.
The Health and Safety Executive advises separating pedestrian and vehicle routes wherever possible and providing clearly marked, protected crossing points where routes meet. Its workplace transport guidance for pedestrians also recommends separate doors for vehicles and people. Security controls should support that layout, not create a new collision risk.
If congestion at a shift change repeatedly causes two vehicles to pass on one access event, the site should review the traffic flow and staffing rather than simply telling the officer to “watch more closely”. Queue length, visibility, barrier position and the time allowed for each check may be part of the problem.
Verify contractors and visitors against the current instruction
A known face is not automatically a current authorisation. Contractors change employers, passes expire, vehicle registrations change and access can be suspended. The officer should use the current approved list or system and contact the named sponsor when information does not match.
Group arrivals should have a group process. For example, a training course, maintenance crew or shift of temporary workers may be checked against a manifest and sponsor rather than individually improvised at the gate. The instruction should say who supplied the list, how changes are approved and what happens to someone not shown.
If someone says their pass is lost, damaged or inside the building, use the replacement or temporary-pass procedure. Do not allow them to follow another user simply because the system cannot be resolved quickly. The separate lost access-card checklist explains the containment and replacement steps.
Use system and CCTV information carefully
An access-control event can show which credential operated a door or barrier, but it may not prove who physically passed through. CCTV may help confirm the sequence when the site’s authorised procedure permits review. The officer should preserve the relevant time reference and report the concern rather than searching widely through footage without a defined purpose.
Do not copy access logs or images into personal messaging accounts. Do not circulate a photograph of the person to staff groups unless the responsible manager has authorised a lawful and proportionate purpose. The record should be available to the people investigating the incident, not become a public warning post.
Repeated events at the same entrance may indicate a procedure, layout, device or training problem. The review should compare the officer’s record with access events, visitor bookings and any relevant video, while avoiding claims about motive that the evidence does not support.
Keep emergency escape and accessibility working
Access control must not prevent emergency escape. The instructions should identify what changes during an evacuation, lockdown, medical emergency or loss of power. An open fire exit during an evacuation is not a normal tailgating event, although re-entry after the emergency may need a separate controlled process.
The site should also account for people who cannot use a turnstile, narrow gate or standard credential reader. An accessible route should provide equivalent verification without forcing someone to disclose unnecessary personal information or wait in an unsafe location.
NPSA guidance on protecting security officers at a facility recommends considering separation of pedestrians, vehicles, staff and visitors at access-control points, as well as lighting, communications and support for officers. These conditions matter when the officer must pause access and ask for verification.
Plan the K9 role separately
A dog-and-handler team may support perimeter or patrol duties, but a dog should not be used to crowd a person at reception or stop a vehicle. The handler needs a safe position away from moving traffic, public queues and the controlled door or barrier.
If a suspected unauthorised entrant moves into the site, the handler should follow the agreed incident instruction. The presence of the dog does not create additional authority to search, detain or pursue. If the handler is expected to support gate access, that duty, the available backup and the limits of the role should be written before the shift.
Record facts, decisions and handover actions
- date, time and access point;
- whether the event involved pedestrians, a vehicle or an authorised group;
- what the officer directly observed;
- the credential, booking or sponsor check requested;
- the person who confirmed or refused authority;
- whether access was granted, denied or abandoned;
- any safety issue, refusal, aggression or system fault; and
- the follow-up owner and next review time.
The next shift should know whether the person or vehicle remains unverified, whether a pass has been suspended, whether CCTV or access records need preservation and whether an entrance is operating under a temporary procedure. “Dealt with” is not a useful handover if another officer could meet the same situation an hour later.
Questions for the access-control briefing
- What counts as tailgating at each pedestrian and vehicle entrance?
- Can a sponsor admit a visitor, or must reception verify them?
- Where should an unverified person or vehicle wait safely?
- What wording and authority does the officer have when challenging access?
- Who provides backup if a person refuses or becomes aggressive?
- How are group arrivals, accessible routes and lost passes handled?
- Who may review access logs and CCTV?
- What changes during an evacuation or system failure?
- Who reviews repeated incidents and changes the process?
Discuss a suitable guarding arrangement
K9 Security Services welcomes enquiries about static guarding, gatehouse presence, access checks and agreed reporting duties for suitable construction, commercial, industrial and vacant sites. Requirements are considered individually by site, duties, shift pattern, access conditions and feasibility; availability must be confirmed for the proposed assignment.
To discuss a requirement, use the security quotation form and include the site postcode, proposed hours, entrance types, expected staff and visitor movements, current access system and the duties security is expected to perform. This article is general operational guidance, not a site-specific security assessment, employment procedure or emergency plan.
Featured image is an existing illustrative access-control image. It does not show a K9 Security Services employee, client site, live gatehouse, tailgating incident, recent job or completed assignment.