Frequently Asked Questions
Straight answers about polygraph testing in Oxford and across Oxfordshire: what it costs, how accurate it is, how to prepare and what happens on the day at Oxford Science Park.
Before You Book
Probably not. People who reach this page have usually been living with the question for a long while before they type it into a search box. Booking a test is not an accusation and it is not a verdict. It is a decision to stop guessing. The common regret is not having booked, it is the months spent deciding whether to.
A short LPI reference and nothing else. The words polygraph, lie detector and Oxford do not appear anywhere on the transaction, so anyone who sees your statement learns nothing from it.
Then no test takes place. We only examine volunteers, and written consent is checked before anything begins, so nobody can be booked in against their will. What the offer does is tell you something either way. A willing yes says one thing. A flat refusal says another. You learn more than you knew, and it costs nothing to find out.
Contact us as early as you can and we will do our best to move your appointment to a day that suits. If you get as far as the car park at Oxford Science Park and are not sure you can walk in, come in anyway and talk to the examiner. Nothing is recorded until every question has been agreed with you, and nobody will push you into anything.
That depends on what the result is, and we will not pretend otherwise. A truthful result gives a couple solid ground to rebuild on. A deceptive one replaces months of confusion with a fact, and facts can be acted on. Either way the written report is evidence rather than instinct. What you do with it is yours to decide, and you are welcome to call and talk it through afterwards.
Understanding Polygraph Tests
A polygraph records your body while you answer a short set of carefully worded questions. Sensors track breathing, blood pressure and pulse, and the electrical activity of the skin. The instrument does not detect lies as such. It records physiological changes, and the examiner scores how your body responded to the questions that matter against how it responded to the comparison questions. On a modern computerised instrument, with a trained examiner and a single issue, decision accuracy sits between 90 and 98 percent.
The whole appointment takes around 90 minutes, and we ask you to allow two hours so nothing is rushed. There are three parts: the pre-test interview, where the issue is discussed and every question agreed; the examination itself, where the sensors are attached and the agreed questions are asked more than once; and the scoring, after which you are told the preliminary result before you leave. The questioning is the shortest part. The preparation and the analysis are what make it reliable.
Three kinds. Relevant questions go to the heart of the issue being tested, for example whether you took the money from the till. Comparison questions are about similar but broader matters and give the examiner something to score the relevant questions against. Neutral questions, such as whether today is a weekday, settle your responses between the others. Every one of them is read to you and agreed in the pre-test interview. Nothing new is introduced once the sensors are on.
Yes, always. Going through the questions with you is a required part of the pre-test interview, not a favour. Your examiner reads each one aloud, checks that you understand exactly what it means, and adjusts the wording until it is clear and fair. By the time the examination starts you know every question by heart. That is what makes the result defensible.
Accuracy and Reliability
A single issue test, properly run, sits between 90 and 98 percent decision accuracy. What decides where in that range you land is not luck: the examiner's training, the instrument, the room and the question technique. The American Polygraph Association's own research base, drawn from hundreds of studies, supports those figures for validated techniques. Check all four factors before you book with anyone.
Your physical state on the day matters: serious fatigue, illness, alcohol or drugs can make charts harder to read. Some medical conditions and medications need to be known about in advance so the examiner can account for them. The room matters, which is why we test in a private, solid-walled meeting room rather than somewhere people come and go. Most of all the examiner matters, because telling ordinary nerves from a deceptive response is a trained skill, not a guess.
No. Everybody arrives nervous, and the scoring does not measure how nervous you are. It compares your responses to different types of question against each other. A truthful person who is shaking and a truthful person who is calm produce the same result. The pre-test interview also settles most people down considerably, because by the end of it there is nothing left to wonder about.
Not as primary evidence, as a rule. UK courts do not generally admit polygraph results, though the test is used by the state in certain supervision settings. Where a result does carry weight is outside the courtroom: in private disputes, family matters, workplace investigations and in a solicitor's assessment of a case. A report often settles the matter long before any court would.
Cost and Pricing
No. If your appointment is more than three days away you can secure it with a £149 deposit, and the balance is collected automatically from the same card two days before your test. Nothing to remember and nothing to pay on the day. The deposit is non-refundable, because it holds that appointment for you alone. If you would rather pay in full, you can, including in three instalments with Klarna.
A single issue examination at John Eccles House is from £449, booked and paid online. The price covers the pre-test interview, the examination and the full written report with the recorded charts, delivered within 24 hours. Couples tests are from £695, theft investigations from £499 and pre-employment screening from £549. Be careful with offers that look too good: the saving usually comes out of the examiner's training or the instrument, and you want neither compromised.
Because payment is what turns a slot on the calendar into a confirmed appointment. The moment you book, a private meeting room is reserved at Oxford Science Park, an examiner is committed to the day and the preparation begins. Pay in full, including in three instalments with Klarna, or, if your test is more than three days away, secure the date with a £149 deposit and have the balance collected automatically two days before. The deposit is non-refundable because the appointment is held exclusively for you from that moment.
For a standard office test, no. The price you see at booking covers the pre-test interview, the examination and the written report with charts, and there is nothing to pay on the day. Home visits are a separate service with their own price, booked online through Home Polygraph Services at https://homepolygraph.com. If you need something unusual, such as a written statement for a solicitor beyond the standard report, ask before you book and we will tell you plainly what it costs.
The couples test at £695 covers two people examined separately on the same issue on the same day, and works out below the cost of two separate bookings. For workplace matters where several members of staff need testing, contact us with the numbers and we will quote for the day rather than per person.
Preparation and Requirements
Sleep properly the night before, eat as you normally would and take any prescribed medication as usual. Avoid alcohol for 24 hours beforehand and go easy on caffeine on the day. Wear something comfortable and not too bulky, because sensors go around your chest and upper arm and on your fingers. There is nothing to revise and nothing to rehearse. The only preparation that matters is deciding to answer truthfully.
Alcohol and recreational drugs for at least 24 hours, and energy drinks or heavy caffeine on the day, because all of them change the charts. Avoid anything you have read online about beating a polygraph. Those methods do not work, examiners are trained to spot them, and attempting them tends to turn a clear result into an inconclusive one. Try not to spend the night before rehearsing the conversation with other people either. Arriving tired and wound up helps nobody.
Usually, yes. Tell us when you book and tell the examiner again in the pre-test interview, particularly about anything affecting your heart, breathing, blood pressure or nervous system. A normal, uncomplicated pregnancy is not a barrier. The examiner assesses suitability before any sensors go on, and if a condition makes a reliable test unlikely on the day they will say so rather than run it regardless.
Keep taking anything your doctor has prescribed. Stopping medication to take a test is never a good idea and does more harm to the charts than the medication would. Beta blockers, blood pressure tablets, anti-anxiety medication, stimulants and antidepressants can all shape the recording, so the examiner needs a full list, including anything bought over the counter. That information is used to interpret the charts correctly, not to exclude you.
Fourteen, as a guide. What really decides it is whether the young person can follow the process, understand the questions and grasp what a lie is, and they must be able to give informed consent themselves. Anyone under 18 also needs written permission from a parent or legal guardian. The examiner spends longer on the pre-test interview with a younger examinee to be sure they understand what is happening.
The Testing Process
The interview is the longest part of the appointment, usually between 45 minutes and an hour. Your examiner goes through the background to the issue, explains how the instrument works and shows you the sensors before any of them go on. Then every question is read to you and agreed. You sign a consent form confirming you are taking the test voluntarily. It is a conversation rather than an interrogation, and most people say it was far calmer than they expected.
Photo ID, such as a driving licence or passport, and nothing else is essential. If there are documents, messages or dates that help explain the issue, bring them, because they can be useful when the questions are being worded. Wear comfortable clothing without thick layers, since the sensors need to sit against your chest, upper arm and fingers. Your confirmation email tells you exactly where to park and what to say at reception.
You are told the preliminary result before you leave the office. The full written report follows by email within 24 hours of your examination. It includes the recorded charts, the examiner's analysis and the formal opinion, laid out in plain English. The gap between the two is deliberate: the charts are scored again, carefully, before anything goes into writing.
The charts recorded during your examination, a description of the technique used and the questions asked, the examiner's analysis of your responses and the resulting opinion on the issue tested. Any factor that may have affected the recording is noted. Reports are reviewed by a second qualified examiner before release. The report is yours to share with whoever you choose, and nobody else receives it.
Privacy and Confidentiality
Yes. Everything said in the room and everything recorded stays between you and the examiner, and the result is released only to the person named on the consent form. We do not discuss your test with anyone else without your written authority. The single exception is a serious safeguarding concern, such as evidence of ongoing harm to a child or vulnerable adult, where we may have a duty to report. If that ever arose it would be discussed with you first.
Whoever is named on the consent form, and no one else. If you book and take the test yourself, that is you. If you take a test that someone else has commissioned, such as an employer, the report goes to them with your consent, which you give before the examination starts. Appointments at Oxford Science Park are staggered, so you will not meet another client on your way in or out either.
Under UK GDPR, on encrypted systems with access limited to the people working on your case. Nothing is sold, shared or passed to third parties. Records are kept for the period our professional standards and the law require and are then securely destroyed. You can ask what we hold about you at any time, and in many cases ask for it to be deleted.
Specific Use Cases
It is the most common reason people book, and it works because it replaces an argument that cannot be won with a fact. One issue is agreed, the questions are worded precisely, and the result is scored from recorded charts rather than from anyone's instinct. It is worth thinking about what you will do with either outcome before you book. Some couples arrange counselling alongside. The test itself is handled with discretion from the first phone call to the report.
Yes, where the role justifies it and the candidate volunteers. Pre-employment screening is used for positions involving money, keys, vulnerable people or sensitive information. It is less common in the UK than in some countries and it has to be done carefully: the candidate must consent in writing and cannot be compelled, and the result should be one part of a fair recruitment process rather than the whole of it. We can also test existing staff during an investigation on the same basis.
Yes, and often its biggest value is in clearing people. When something goes missing and several staff had access, suspicion spreads across all of them. Single issue testing, one person at a time and entirely voluntary, lifts that cloud from those who had nothing to do with it and narrows the question for the employer. Results should sit alongside the rest of an investigation, not replace it, and employment decisions need the usual fair process.
Not as evidence before a UK court in the normal way, but that is not the same as useless. Solicitors commission tests to assess credibility, inform strategy and support negotiation. In family disputes, parties sometimes agree between themselves to be guided by a result. In civil matters it can shift a settlement discussion. Ask your solicitor how a report might help in your particular situation before you book.
Additional Common Questions
A deceptive result means the charts showed significant responses to the relevant questions. The examiner will talk it through with you before you leave, because occasionally a misunderstood question or an unrelated worry explains part of a chart and a retest is appropriate. When the charts are consistent, though, they are consistent. The polygraph does not say why someone responded as they did. It records that they did, and the report sets that out plainly for whoever is named on the consent form.
You can stop the examination at any point, since taking it is voluntary from start to finish. Refusing one of the agreed questions once the sensors are on is different: it leaves the test incomplete and that is recorded. The time to object to a question is the pre-test interview, when the wording is still open and the examiner can change it. Once you have agreed the questions, answering all of them is what makes the result mean something.
Roughly one test in ten comes back inconclusive, which means the charts did not give the examiner enough to call either way. It is not a failed result and it does not suggest you lied. Causes include tiredness, illness, medication, too much movement during the recording or a question that turned out to be ambiguous. The examiner will explain what they saw and, where it makes sense, arrange a retest once the cause has been dealt with.
The office test takes place at Oxford Science Park, which sits off the southern ring road and is a straightforward drive from most of Oxfordshire. If attending the office is genuinely not possible, or you require an evening or weekend test, our home visit service runs seven days a week with the last examination starting at 8pm, booked online through Home Polygraph Services at https://homepolygraph.com.
Yes. The business centre at John Eccles House has a reception area where a companion can wait while the examination takes place. Only you and the examiner are in the room during the test itself. Your confirmation email explains what to say when you arrive.
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