How Much Does a Lie Detector Test Cost?

Updated on August 26, 2026 | Written by Alec Pow
This article was researched using 11 sources. See our methodology and corrections policy.

A professional lie detector test, more accurately called a polygraph examination, currently costs about $300 to $900 for many private single-person tests in the United States. Current published examples include $300 to $500 for basic or relationship exams in Texas and Alaska, $600 to $700 for criminal exams from the same examiner, and $550 to $875 for standard single-issue tests at California offices. Higher-cost locations, multiple examinees, travel, attorney-related work, expert testimony, or separate issues can push the bill above $1,000.

The useful price question is not just how much the appointment costs. A $500 polygraph may have little practical value if an employer is legally barred from requesting it, a court will not admit it, the test tries to cover several unrelated accusations, or the examiner lacks the training required for the intended use. The quoted fee should state what issue will be tested, what the deposit policy is, whether a written report is included, and whether testimony or travel costs extra.

A polygraph does not directly detect a lie. It records physiological activity, including respiration, cardiovascular responses, and electrodermal activity, while an examiner administers a structured series of questions and evaluates the resulting charts.

Article Highlights

• Current private single-person polygraph examples run from about $300 to $875 (at $30 per hour, earning that amount would take about 1.3 to 3.6 full-time workdays, before taxes), with many falling around $400 to $700.
• A current Texas provider charges $400 for a basic or relationship exam and $600 for a criminal exam in Texas.
• A current California provider lists standard single-issue examinations at $550 to $875, depending on office location.
• A $100 booking deposit is common in several current pricing examples, but refund rules differ by provider.
• Most U.S. private employers are prohibited from requiring or requesting lie-detector tests for applicants or employees, subject to limited federal exceptions.
• Polygraph admissibility in court varies by jurisdiction and circumstances, so a lawyer should be consulted before paying for a test intended for litigation.
• Accuracy remains disputed. Industry research reports stronger results than independent scientific reviews, especially for narrowly focused incident-specific testing.

How Much Does a Lie Detector Test Cost?

Current example	Published price	What it covers
Tyler, Texas basic/relationship test	$300 (about 1.3 full-time workdays at $30 per hour)	Private basic or relationship polygraph
Fort Worth, Texas basic/relationship test	$400	Private basic or relationship polygraph
Texas criminal polygraph	$600	Criminal-case examination
Mat-Su Valley, Alaska criminal polygraph	$700	Criminal-case examination
California standard test	$550 to $875	One person, one issue, pre-test work, examination, analysis, and report

Current examiner pricing from Polygraph & Investigations lists basic or relationship exams at $300 in Tyler, Texas, $400 in Fort Worth, and $500 in Alaska’s Mat-Su Valley. Criminal exams are listed at $600 in Texas and $700 in Alaska. The provider states that every appointment requires a $100 nonrefundable deposit.

A separate 2026 California price schedule lists standard one-person, one-issue testing at $550 to $875 depending on office. That fee includes the pre-test assessment, examination, chart analysis, verbal result, and written report. The provider uses a $100 deposit, but its stated refund terms differ from the Texas provider’s nonrefundable policy.

These examples are more useful than adding imaginary charges for equipment calibration, question writing, and chart scoring. Many private examiners sell the examination as one package. Ask what is included before comparing two quotes.

The $100 Deposit Math

The booking deposit can represent a surprisingly large share of a lower-priced examination. Using the current Texas provider’s $100 (about 3.3 hours of work at $30 per hour) nonrefundable deposit, a $400 Fort Worth relationship test requires $100 ÷ $400 = 25% of the total price upfront.

For its $600 Texas criminal examination, the same deposit equals 16.7% of the fee. On the $700 Alaska criminal exam, it equals about 14.3%.

Worked example: suppose one person books the $400 relationship test and pays the $100 nonrefundable deposit. The remaining balance is $300. If that person cancels under terms that cause the deposit to be lost and later books a $550 test elsewhere, the combined cash spent becomes $100 + $550 = $650. Deposit and cancellation rules belong in the price comparison before the first appointment is booked.

One Issue Can Cost Less

Polygraphs are not priced by how many accusations a client can squeeze into the appointment. A focused examination is designed around a defined issue and carefully reviewed relevant questions. The American Polygraph Association’s public FAQ says relevant questions in a specific-issue examination focus on the particular act under investigation, and all test questions are reviewed with the examinee during the pre-test interview.

One current California service defines its standard price as one person and one issue, with up to three relevant questions. If a case contains genuinely separate issues, it says separate examinations may be needed. That can turn one $700 test into two $700 tests, or $1,400, if two unrelated matters must be examined separately.

Trying to force several unrelated allegations into one test just to save money can change the test design and the usefulness of the result. The examiner should decide whether the requested topics belong in one examination before the client pays the full fee.

Most Employers Cannot Require One

The U.S. Department of Labor states that the Employee Polygraph Protection Act usually prohibits most private employers from requiring or requesting lie-detector tests from job applicants or employees. Employers also usually cannot use, accept, refer to, or inquire about test results where the Act applies.

There are limited exceptions. The Department of Labor’s EPPA guidance describes restricted testing for certain security-service and pharmaceutical jobs, plus certain investigations of employees reasonably suspected of involvement in a workplace incident that caused a specific economic loss. Federal, state, and local government agencies are outside the Act’s general private-employer prohibition.

That distinction matters before paying for a supposed “pre-employment polygraph.” Police, corrections, intelligence, and other government hiring processes can use polygraph screening under rules that differ from ordinary private-sector hiring. For conventional employer screening, our background check cost guide covers a much more common employment-screening expense.

Will a Court Use the Result?

A private polygraph report is not automatically admissible evidence. Rules vary by jurisdiction, case type, stipulations between the parties, evidentiary rules, and the judge’s rulings. Someone considering a test to help a criminal or civil case should ask the attorney handling the matter whether the result would serve any useful purpose before paying the examiner.

In United States v. Scheffer, the U.S. Supreme Court upheld the military’s categorical exclusion of polygraph evidence and noted continuing disagreement over polygraph reliability. The decision also recognized that jurisdictions have taken different approaches to admissibility.

A test can still be used outside a trial for investigative, negotiation, probation, treatment, or attorney-strategy purposes in some settings. That is different from saying a $600 private exam will “prove innocence” to a jury.

Legal-use scenario: a defendant could spend $600 on a private criminal polygraph and receive a written report, yet still gain no admissible trial evidence if the governing court excludes it. Asking counsel first can prevent the entire $600 from becoming a legal-strategy cost with no courtroom use.

How Accurate Is a Polygraph?

The answer depends heavily on which research base is used. The American Polygraph Association’s industry meta-analysis reports an aggregated decision accuracy of 89% for event-specific diagnostic techniques, with an estimated 11% inconclusive rate. Techniques that covered multiple issues had a lower aggregated decision accuracy of 85% and an estimated 13% inconclusive rate.

Independent scientific reviews are more skeptical. The American Psychological Association’s 2025 review says physiological responses associated with lying can also occur when a truthful person is nervous. It notes that the industry accuracy analysis was not independently conducted and summarizes continuing concerns about the scientific basis of polygraph testing.

The National Academies’ scientific review found that specific-incident testing can distinguish deception above chance but is far from perfect. It found broader screening particularly problematic because even a modest false-positive rate can incorrectly flag many truthful people when the target behavior is rare.

A polygraph result should not be described as direct proof that someone lied. The instrument records physiological reactions and the examiner interprets those data within a testing method.

What the Fee Should Include

A normal professional examination includes more than the period when sensors are attached. The APA describes a pre-test interview, chart-collection phase, and data-analysis phase. During the pre-test portion, the examiner reviews the issue, completes paperwork, explains the procedure, and discusses the questions before data collection begins.

Before paying, ask whether the quoted fee includes:

• case review and the pre-test interview
• question development and review
• the full chart-collection session
• scoring and examiner analysis
• same-day verbal findings, if offered
• a written report
• office or venue charges
• travel when testing is performed elsewhere

Expert testimony, attorney conferences, jail or prison travel, on-site testing, multiple examinees, or a second independent examination can sit outside the standard fee. A written quote is much more useful than an itemized national “average” that assumes every examiner bills the same way.

Check the Examiner

Polygraph licensing varies by state. The APA’s current state licensing directory lists states such as California and Florida as having no state polygraph-license requirement while identifying regulatory boards in states including Texas. A lack of a state license requirement does not mean training and professional standards are irrelevant.

Ask where the examiner trained, whether that program is recognized by a professional organization, whether state licensing applies, how often the examiner performs the type of test you need, what technique will be used, and what documentation you will receive. Membership in a professional association can be one credential to check, but it is not a substitute for matching the examiner’s experience to the case.

For an employment test that falls within an EPPA exception, federal rules impose examiner requirements as well. The Department of Labor says an examiner must hold a valid state license where one is required and must maintain at least $50,000 in bond or professional liability coverage.

When Paying for a Polygraph Makes Sense

Makes sense if:

• The issue is narrow enough for a properly designed specific-incident examination.
• Both sides understand what they will and will not infer from the result.
• An attorney has confirmed that a legal-case test has a useful purpose before the fee is paid.
• The examiner’s training, applicable license, report format, deposit policy, and full price have been checked.

Does not make sense if:

• A private employer is requesting a pre-employment test without first establishing that an EPPA exception applies.
• The client expects the machine to provide infallible proof of truth or deception.
• Several unrelated accusations are being packed into one exam only to avoid paying for separate tests.
• Neither person in a relationship dispute is willing to accept any possible result.

What We Verified

• Checked current 2026 state pricing examples and confirmed that private single-person fees vary materially by location rather than following one national rate.
• Confirmed the current Department of Labor restrictions before describing private-sector employment testing and its limited exceptions.
• Cross-referenced industry and independent scientific sources instead of presenting one disputed accuracy percentage as settled fact.
• Verified current professional licensing resources before recommending that consumers look for a single nationwide “polygraph certification.”

Related Screening and Monitoring Costs

A polygraph is only one type of investigative or compliance expense. Employers and individuals may encounter separate drug and alcohol testing costs, while criminal-justice supervision can include the very different expense of an ankle monitor. Those services answer different questions and should not be treated as substitutes for a polygraph.

Answers to Common Questions

How much does a lie detector test cost?
Current private examples range from about $300 to $875 for many single-person examinations. A practical budget for a private single-issue test is about $400 to $900, while specialized legal work, travel, multiple issues, or multiple examinees can cost more.

How much does a relationship polygraph cost?
One current provider lists basic or relationship exams at $300 in Tyler, Texas, $400 in Fort Worth, and $500 in Alaska’s Mat-Su Valley. Other providers and locations can charge more.

How long does a polygraph take?
A private single-issue appointment often takes roughly 90 minutes to several hours, including the pre-test interview, question review, data collection, analysis, and discussion. Case complexity and the testing method affect the time.

Can an employer make me take a lie detector test?
Most private U.S. employers usually cannot require or request one under the Employee Polygraph Protection Act. Narrow exceptions exist, and federal, state, and local government employment is treated differently.

Can a polygraph be used in court?
Sometimes, but admissibility varies by jurisdiction and circumstances. If the purpose is litigation, ask the attorney handling the case before spending money on a private examination.

Are lie detector tests 90% accurate?
There is no universally accepted accuracy number. An industry meta-analysis reports 89% decision accuracy for certain event-specific methods, while independent scientific reviews raise substantial concerns about error rates, research quality, and screening applications.

What does a polygraph actually measure?
It records physiological activity such as respiration, cardiovascular responses, and electrodermal activity while questions are asked. The machine does not directly measure lying or read a person’s thoughts.

Disclosure: This article provides general cost and legal-context information, not legal advice. Employment rules, licensing requirements, evidentiary rules, examiner practices, and prices vary by jurisdiction and case. For a test connected to employment, criminal charges, civil litigation, probation, or another legal matter, check the applicable rules or consult a qualified attorney before relying on a private polygraph result.