Private polygraph examiner
Run consent-based lie-detector tests for individuals and solicitors, in hired rooms or at the client's chosen venue.
- £4k-12k
- Side hustle
- Out and about
Estimates for a small start in the UK, not guarantees.
Official data
1,821 UK companies in this field, 23% registered in the last 2 years
SIC 80300 “Investigation activities”. Source: Companies House, November 2026.
What it is
You carry out voluntary polygraph examinations using a computerised polygraph. Each one includes a pre-test interview, the test itself and a written report. You usually work from hired meeting rooms or serviced offices near the client, and travel to them.
Your first three steps
- Research accredited polygraph training courses and what professional bodies expect from examiners
- Price up equipment, professional indemnity and public liability insurance, and a few rooms you could hire by the hour
- Draft a consent form and a plain-English explanation of what a test can and cannot show, then show it to a solicitor
Who pays
Individuals with a personal dispute or concern, and solicitors or investigators wanting supporting information. Work for employers is a sensitive area and should only be considered after taking legal advice.
How it makes money
A fixed fee per examination, usually with a charge for the report and for travel outside your local area. Work tends to come in occasional bookings rather than a steady flow.
Skills that help
- Calm, neutral interviewing manner
- Careful report writing
- Discretion with sensitive information
- Completing a recognised polygraph training course
Watch out for
- Polygraph results are generally not accepted as evidence in UK courts, so never promise they will settle a legal case
- Tests must be voluntary with written consent, and consent may not be genuinely voluntary if an employer asks or pressures a worker or job applicant
- Testing for employers has strict legal limits (for example under employment law, UK GDPR and data protection rules), so take legal advice before offering it and do not assume it is allowed
- You will handle sensitive personal data, so check whether you need to pay the data protection fee to the ICO and what UK GDPR duties apply
- Professional indemnity as well as public liability insurance is worth checking, because complaints could be serious
- Check whether any rules for investigators or local requirements apply to your type of work; polygraph examining is not generally a licensed activity, but confirm with the relevant regulator or your council
- Training and equipment can be costly and demand is uncertain, so test the market before you spend
Deep research report · UK
Everything you need to start: private polygraph examiner
Researched with live web search for United Kingdom: real startup prices, the licences and rules, what others charge, a break-even example, how to find your first customers and a 30-day launch plan. With sources.
- Startup costs with real prices
- Licences, registration and rules
- Pricing: what others charge
- Break-even example
- Finding your first customers
- 30-day launch plan
- Risks and how to reduce them
Questions people ask
How much does it cost to start a polygraph examiner business?
Startup costs are typically around £4,000 to £12,000, depending on your training course, equipment and room hire. These are estimates. Training and equipment can be costly and demand is uncertain, so test the market before you spend.
How much can a private polygraph examiner earn?
Monthly revenue is typically around £400 to £3,000, depending on how many examinations you carry out and your hours. The estimates start from about 6 hours a week. Demand is uncertain, so it is worth testing the market first.
What rules should I check before offering polygraph tests?
Check that tests are voluntary with written consent, and never promise results will settle a legal case, as they are generally not accepted as evidence in UK courts. Take legal advice before testing for employers, and check ICO data protection fee and UK GDPR duties.
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