Have you ever wondered what it’s like to take a lie detector test, also known as a polygraph exam? If you’ve been asked to take one for the first time, it can be quite intimidating. In this article, we will guide you through what you can expect during a polygraph exam in the UK, so you can feel more prepared and less anxious.

Operational Process of Polygraph Examination

The process of conducting a polygraph examination involves three phases, which are as follows:

Pre-Test Phase (Information Collection, Relevant Questions/Statements Formulation)

During this first stage, the examiner will gather information from the examinee/client regarding the specific issue under investigation. The examiner will formulate and review with the examinee/client all the questions that will be asked during the polygraph examination. The examinee will be provided with a detailed explanation of the polygraph procedure, as well as the polygraph instrument and its components.

In-Test Phase – Polygraph Examination (Chart Collection)

The polygraph examination takes place during this second phase. Just before beginning the examination, the examiner will inflate the blood pressure cuff to a pressure of 60 mmHg. The examiner will then ask the examinee the series of questions that were formulated and reviewed during the pre-test interview. As the examinee answers the questions, his or her physiological data will be continuously collected, measured, and recorded by the polygraph instrument. The examinee will have a relaxation period of approximately two minutes between each series of questions.

Post-Test Phase (Data Analysis, Scoring Procedure, Results)

During this final phase, the examiner will analyse and evaluate the physiological data collected during the test by means of a scientifically-based numerical quantification system, and will render one of the following results: No Deception Indicated (the examinee is telling the truth), Deception Indicated (the examinee is not telling the truth), or Inconclusive (the evaluation of the examinee’s physiological data is inconclusive).

Polygraph Instrument

The computerised polygraph instrument collects, measures, and records physiological data obtained from three major systems in the human body, all of which are controlled by the Autonomic Nervous System. These systems are the Cardiovascular System (heart rate, relative blood pressure, blood volume), Respiratory System (respiratory activity), and Electrodermal System (Galvanic skin response, i.e., sweat gland activity).

Before beginning the polygraph examination, the examiner will administer a stimulation/calibration test to obtain the examinee’s physiological baseline and ensure that he or she is a suitable candidate to undergo a polygraph examination.

Polygraph Examination Report

Upon completion of the polygraph examination, the examiner will provide the client with a verbal result. A written verified report detailing the information received during the polygraph procedure and the examination result will be sent to the client (at no extra cost) within 24 hours after the test completion.

Systems and Methodology

All polygraph examinations are conducted in accordance with the Code of Ethics and the set of Standards and Principles of Practice required by the American Polygraph Association (APA) – the world’s leading association dedicated to the use of evidence-based scientific methods for credibility assessment. Our firm utilizes state-of-the-art digital polygraph systems from Lafayette Instruments (a global leader in polygraph instrumentation).

Booking and Confirmation Phase

The booking process is automated, secure and designed to take only a few minutes to complete. Once the services of our firm have been retained by clicking on the button ”Book Now” and paying the required deposit of £150 (Fees and Cancellation policy apply), the requester of the lie detector test (polygraph examination), also referred to as “the client” will receive an email with a link to our pre-examination assessment form which should be filled and submitted online no later than 48 hours after the deposit has been made. Shortly after paying the remaining balance for the requested test(s) using one of our secure payment methods integrated into our form, the client will receive a final confirmation email with the date/time


Taking a polygraph exam can be nerve-wracking, but it’s important to remember that being nervous won’t affect the test’s outcome. The procedure can take anywhere from one to three hours, and while there are established protocols for polygraph testing, many examiners will use variations of the basic technique based on personal experience and preference.

If you’re asked to take a polygraph exam in the UK, remember to stay calm, be honest, and follow the examiner’s instructions. Taking the test seriously and following the protocol can help ensure a successful outcome.