Lie detector tests, also known as polygraph examinations, have become increasingly popular in the UK for various purposes, including criminal investigations, employment screening, and resolving private disputes. The cost of a lie detector test can vary depending on several factors, and this guide aims to provide you with an overview of the expenses involved in conducting a polygraph examination in the UK.

Factors Influencing the Cost of a Lie Detector Test

  1. Examiner’s expertise and experience: The fees for a lie detector test may depend on the examiner’s qualifications, accreditation, and experience. Professionals with extensive experience and a proven track record may charge more for their services.
  2. Location: The cost of a polygraph test may vary depending on the location where the examination is conducted. Tests performed in major cities or metropolitan areas might be more expensive due to higher operational costs.
  3. Purpose of the test: The complexity and scope of the polygraph examination can also influence the price. Tests for legal or forensic purposes may be more costly than those conducted for private or personal reasons.
  4. Number of questions and issues: The number of questions or issues addressed during the examination can also impact the cost. More questions typically require more time, which can increase the fees.
  5. Additional services: Some polygraph examiners may offer additional services, such as a written report or expert witness testimony, at an extra charge.

Average Costs

The average cost of a lie detector test in the UK ranges from £400 to £800, depending on the factors mentioned above. However, it’s essential to consider that the cheapest option may not always be the best choice. It is crucial to prioritize the examiner’s qualifications and the test’s reliability to ensure accurate results.

Here’s a breakdown of the possible costs

  • London and South East: £400 – £600
  • South West: £400 – £600
  • Midlands and East Anglia: £400 – £600
  • North West and North East: £400 – £600
  • Scotland: £700 – £900
  • Wales: £400 – £600
  • Northern Ireland: £500 – £700

Please note that these prices are approximate and may vary depending on the specific circumstances of each test, the examiner’s expertise, and other factors discussed earlier in the guide.

  • Basic lie detector test: £400 – £600
  • Comprehensive lie detector test (including a written report): £400 – 450
  • Expert witness testimony (if required): Additional fees may apply.


When considering a lie detector test in the UK, it’s vital to understand the factors that can influence the cost. While price is a crucial consideration, it’s essential not to compromise on the quality and accuracy of the examination. Ensure you choose a reputable, certified, and accredited polygraph examiner to achieve the most reliable results.

By being well-informed about the costs involved, you can make a more informed decision when selecting a professional to conduct a lie detector test, whether it’s for personal, legal, or employment-related purposes.