How Much Does a Polygraph Cost in the UK? - British Polygraph Society

This guidance note is intended for members of the public, solicitors, and organisations considering commissioning a private polygraph examination in the United Kingdom. It sets out indicative price ranges, explains what a fee should cover, identifies pricing red flags, and suggests questions to ask before booking. The British Polygraph Society does not set, recommend, or regulate fees; the figures quoted below are approximate market ranges and should be verified independently before relying upon them.

Key Points

Private polygraph examinations in the UK typically range from approximately £400 to £1,000 depending on type and complexity.
Fees must never be contingent on the outcome of the examination — this is prohibited by the BPS Code of Ethics, §3.2.^[1]
A compliant examination must be scheduled for no fewer than 90 minutes and must include a written report.^[2]
All fees should be agreed in writing with the retaining party before the examination takes place.^[3]
Audio or audio-video recordings of the examination must be maintained for a minimum of one year.^[4]

Indicative Price Ranges

Important: The British Polygraph Society does not set, endorse, or regulate examination fees. The figures below are approximate market observations and may not reflect the price you are quoted. Always obtain a written quotation from the examiner directly.

Pricing for polygraph examinations in the UK varies considerably depending on the type of examination, the examiner’s qualifications and experience, the location, and the complexity of the issue under investigation. The following table provides broad indicative ranges; actual fees should be confirmed with the examiner at the time of enquiry.

Examination Type	Indicative Range	Notes
Private / relationship / fidelity	£400–£800	Single-issue examination for an individual
Corporate / pre-employment screening	£500–£1,000	May involve additional legal and HR liaison
PCSOT (post-conviction sex offender testing)	Varies by contract	Typically commissioned by probation services or treatment providers; pricing is usually set by contract
Legal / solicitor-instructed	£500–£1,000+	May include preparation of a report suitable for court or conference

Higher fees do not automatically guarantee a better examination, and lower fees are not necessarily a sign of poor quality. What matters is that the examination is conducted in accordance with recognised professional standards and that the fee covers all of the components described below.

What Should the Fee Include?

A polygraph examination is not a single event but a structured process comprising several phases. When you receive a quotation, check that the fee covers the following as a minimum.

Pre-test interview

This is the phase during which the examiner reviews the background of the case, explains the testing procedure, discusses the questions that will be asked, and obtains informed consent. A thorough pre-test interview is essential to the validity of the results.

In-test (chart collection)

The actual physiological recording phase, during which the examinee is connected to the polygraph instrument and the question series is administered. This typically involves multiple chart presentations.

Post-test interview

After chart collection, the examiner analyses the data and may discuss the preliminary findings with the examinee and, where appropriate, the commissioning party.

Written report

A written report is a mandatory deliverable. The BPS Standards of Practice at §10.5 requires that a written report be produced following every examination.^[5] If a provider does not include a written report in the fee, this should be treated as a significant concern.

Recording retention

Examinations must be recorded by audio or audio-video means, and these recordings must be retained for a minimum of one year.^[6] This protects both the examinee and the commissioning party.

Minimum duration

The BPS Standards of Practice at §8.10 stipulates that examinations must be scheduled for no fewer than 90 minutes.^[7] An examination that is rushed into 30 or 45 minutes is unlikely to include an adequate pre-test interview, sufficient chart presentations, or meaningful post-test analysis.

Red Flags on Pricing

Misconception: “You only pay if you fail”

This is not how ethical polygraph practice works. Any fee arrangement where the cost depends on whether the examinee is found truthful or deceptive is expressly prohibited. The BPS Code of Ethics at §3.2 states that fees shall not be contingent on findings or results, and §3.2 provides that no fee may be varied as a consequence of the opinion rendered.^[8]

The following pricing practices should be treated as warning signs when evaluating a prospective examiner:

Outcome-contingent fees. Any arrangement where the fee depends on the result — for example, “free if you pass” or a surcharge for a deceptive outcome — is a serious ethical violation.^[9]
No written report included. A written report is a required component of every examination.^[10] A provider who charges extra for a report, or does not offer one at all, may not be adhering to professional standards.
Unrealistically low pricing. A fee significantly below the ranges quoted above may indicate that the examiner is cutting corners — for example, by shortening the examination below the 90-minute minimum,^[11] omitting the pre-test interview, using substandard equipment, or running an excessive number of examinations per day. The BPS Standards of Practice limits examiners to a maximum of five examinations per day.^[12]
Fees not agreed in writing beforehand. The BPS Code of Ethics at §3.3 requires that fees be agreed in writing with the retaining party before the examination.^[13] An examiner who is vague about pricing or who does not provide a written fee agreement before the appointment should be viewed with caution.
Extra charge for “passing.” Any fee structure that rewards or penalises based on the outcome is prohibited, regardless of how it is described.^[14]

What Drives Cost?

Several factors influence the fee an examiner charges. Understanding these may help you evaluate whether a quotation is reasonable.

Examiner qualifications and experience. Examiners who hold recognised professional certifications and have completed accredited training programmes may charge higher fees. You can search the BPS examiner directory to identify members, though listing in the directory does not itself constitute an endorsement of any particular fee level.
Instrumentation. Modern computerised polygraph instruments represent a significant investment. The quality and maintenance of the equipment used can affect cost.
Location. Examinations conducted in the examinee’s area may attract travel and venue costs. Some examiners maintain dedicated testing rooms; others travel to the client. Travel-inclusive fees may be higher, particularly outside major cities.
Complexity. A straightforward single-issue examination (for example, a specific allegation of infidelity) is generally less costly than a multi-faceted investigation requiring detailed case review and the development of bespoke test questions.
Specialism. Certain areas — such as PCSOT, legal proceedings, or corporate investigations — may require specialist training or additional professional indemnity insurance, which can affect pricing.

Questions to Ask Before Booking

Before committing to an examination, consider asking the examiner or provider the following questions. For broader guidance on how to choose a polygraph examiner, see our separate guidance note.

What is the total fee, and what does it include? Confirm that the pre-test interview, in-test phase, post-test review, written report, and recording retention are all included.
Will the fee be confirmed in writing before the examination? This is a requirement under the BPS Code of Ethics §3.3.^[15]
Is the fee the same regardless of the outcome? Any hesitation or qualification on this point is a red flag.^[16]
How long will the examination take? It should be scheduled for no fewer than 90 minutes.^[17]
Will the examination be recorded? Audio or audio-video recording is a standard requirement.^[18]
What are your qualifications and professional memberships? Consider checking whether the examiner is listed in the BPS directory or holds other recognised credentials.
What is your cancellation policy? Understand any charges that may apply if you need to reschedule.
Are there any additional costs (travel, venue hire, supplementary reports)?

VAT, Contracts, and Cancellation

Some examiners are VAT-registered, in which case their quoted fee may or may not include VAT at the applicable rate. Always ask whether the quoted price is inclusive or exclusive of VAT.

Where an examination is commissioned by a solicitor, employer, or other organisation, a more formal contract or letter of engagement may be appropriate. Such contracts should address the scope of the examination, the fee (including any disbursements), the timetable for delivery of the report, data retention and confidentiality obligations, and the cancellation policy. For guidance on organisational commissioning, see our page on commissioning a polygraph.

For individual bookings, at minimum you should expect to receive written confirmation of the fee and what it covers before the appointment, consistent with the Code of Ethics §3.3 requirement.^[19]

Glossary

BPS: British Polygraph Society — an unincorporated UK membership body for polygraph professionals, founded in 2017.
Code of Ethics: A set of ethical rules published by the BPS governing the professional conduct of its members, including fee arrangements and conflicts of interest.
Standards of Practice: A set of procedural requirements published by the BPS covering how polygraph examinations should be conducted, including minimum duration, recording, and reporting obligations.
PCSOT: Post-Conviction Sex Offender Testing — a specialised form of polygraph examination used in the supervision and treatment of convicted sex offenders.
Pre-test interview: The phase of a polygraph examination before chart collection, during which the examiner reviews the case, explains the procedure, discusses the test questions, and obtains informed consent from the examinee.
Chart collection (in-test): The phase during which physiological data are recorded from the examinee via the polygraph instrument while test questions are presented.
Post-test interview: The phase following chart collection in which preliminary results may be discussed with the examinee and/or the commissioning party.
Written report: A formal document produced after the examination setting out the background, methodology, findings, and opinion of the examiner. Required by BPS Standards of Practice §10.5.
HMPPS: His Majesty’s Prison and Probation Service — the executive agency responsible for administering the statutory polygraph testing regime for certain offenders in England and Wales.
VAT: Value Added Tax — a consumption tax charged on most goods and services in the UK. Whether a polygraph fee is subject to VAT depends on the examiner’s registration status.
CPD: Continuing Professional Development — ongoing training and education undertaken by professionals to maintain and develop their competence.
Retaining party: The person or organisation that commissions and pays for the polygraph examination. This may be the examinee, a solicitor, an employer, or another body.

Sources

British Polygraph Society (2020). Code of Ethics, v1.0, §§3.1–3.3. Available at: polygraph.org.uk/standards-ethics/code-of-ethics/.
British Polygraph Society (2020). Standards of Practice, v1.0, §§8.5, 8.10, 10.5. Available at: polygraph.org.uk/standards-ethics/standards-of-practice/.

This guidance note is published by the British Polygraph Society for general information purposes. It does not constitute legal, financial, or professional advice. BPS does not set, recommend, or regulate polygraph fees. The indicative price ranges quoted are approximate market observations and may not reflect current pricing. Readers considering booking a polygraph examination should obtain a written quotation directly from the examiner and, where appropriate, take independent advice. For further information on choosing an examiner, see the BPS guidance on how to choose a polygraph examiner. For information about your rights as an examinee, see Your Rights.