Hiring a private detective typically costs between $2,000 and $10,000 for a full case, built from hourly rates that run $70 to $200 in most markets. A basic background check might come in under $300. A weeks-long surveillance operation or a corporate fraud investigation can run well past $10,000. The final number depends on how the investigator bills, what the case demands in hours and equipment, and where the work happens.
How Private Investigators Bill
Three billing models cover almost every engagement, and many cases combine them.
Hourly Rates
Hourly billing is the default for open-ended work, especially surveillance, where no one can predict how many hours a job will require. Rates generally fall between $70 and $200 per hour. Investigators with specialized skills in digital forensics or corporate fraud can charge $250 or more. Location shifts the range: a large metro area typically runs above $100 per hour, while smaller markets sit at $70 to $90.
Flat Fees
When the task is well-defined, investigators quote a single price. Basic background checks covering criminal history and public records typically run $100 to $300. Deeper searches into financial history, employment verification, or relationship checks run $300 to $700. Skip traces to locate a missing person generally cost $250 to $1,000, depending on how cold the trail is. The advantage is that you know the total before work begins.
Retainers
Larger or ongoing cases usually require a deposit up front, typically $500 to $5,000. The investigator bills time and expenses against that balance and gives you an accounting of how it was spent. If the retainer runs out mid-case, you replenish it. Any unused portion should be refunded when the work is done. A simple locate job might need $500 up front; a multi-week surveillance operation could need several thousand.
What Drives the Final Price
Two cases that sound similar on the surface can cost wildly different amounts. A handful of factors do most of the work.
- Case complexity. A corporate embezzlement investigation involving financial records, interviews, and forensic accounting will cost several times what a straightforward infidelity surveillance costs. More complexity means more hours, more specialized skills, and often more than one investigator on the job.
- Duration. Surveillance is the least predictable line item. A full day of surveillance by a single investigator runs roughly $600 to $1,200. Multi-investigator operations can exceed $1,500 per day. Weeks of coverage add up quickly.
- Geographic location. Beyond the base-rate difference between cities and smaller markets, travel outside the investigator’s home area means you also pay for mileage, lodging, and per diem.
- Urgency. Rush requests that bump other cases or require immediate deployment often carry a premium of 25 to 50 percent above the normal rate.
- Specialization. Cyber investigations, insurance fraud, and forensic accounting require training and tools that justify higher rates. Generalist work on basic surveillance or background checks costs less.
Expenses on Top of the Base Fee
The hourly rate or flat fee is rarely the whole bill. Most investigators pass through certain out-of-pocket costs, and a good service agreement spells them out ahead of time.
Travel and Mileage
Mileage reimbursement is nearly universal for fieldwork. Many investigators peg their rate to the federal standard, which is 72.5 cents per mile for 2026.1Internal Revenue Service. IRS Sets 2026 Business Standard Mileage Rate at 72.5 Cents Per Mile Some charge slightly more or less, so check the agreement. Out-of-town assignments add airfare, hotel, rental cars, and meals, typically billed at cost.
Equipment and Technology
Specialized gear like long-range cameras, covert video equipment, or forensic software may be billed as a separate daily or per-use fee, often $100 to $500 per day. Not every case needs special equipment, but surveillance and digital forensics cases frequently do.
Database and Records Searches
Investigators subscribe to proprietary databases that pull public records, court filings, and financial data that a basic internet search won’t surface. Access fees typically run $25 to $200 per query, depending on the database and the depth of information requested. These costs are usually passed through to you.
Court Testimony and Written Reports
If your case heads to court, expect separate charges for testimony. Investigators appearing as expert witnesses typically bill $300 to $600 per hour for testimony, with some highly credentialed experts charging more. Travel time to and from the courthouse is often billed at a reduced rate. Detailed written reports compiling evidence, timelines, and findings are sometimes included in the base fee but often billed separately, ranging from $150 to $750 depending on complexity and length.
Legal Limits Worth Knowing Before You Pay
Money spent on illegally obtained evidence is money wasted. Evidence gathered outside the law is typically inadmissible in court, and you can face personal liability if you knowingly directed or benefited from illegal methods.
Federal law prohibits intercepting phone calls, placing hidden recording devices, or tapping into electronic communications without proper authorization. Violations carry penalties of up to five years in prison and substantial fines.2Office of the Law Revision Counsel. United States Code Title 18 – Section 2511 Private investigators are not law enforcement and cannot obtain wiretap warrants. Any investigator who says they can record private phone conversations is either lying or breaking the law. Many states go further and require all-party consent for recording conversations.
GPS tracking has no single federal rule for private citizens or investigators; the rules are set state by state and vary dramatically. Some states allow a vehicle owner to consent to tracking their own car, while others treat placing any tracker without the subject’s knowledge as a criminal offense. Ask the investigator to explain the specific legal authority in your state before agreeing to GPS surveillance. A vague answer is a red flag.
Investigators may conduct surveillance from public places and access public records, but they cannot enter private property without permission, impersonate law enforcement, hack into email or social media accounts, or use deception to access protected records like medical files or bank statements. If anyone offers to get you information “no matter what it takes,” walk away.
Verify the License Before You Hand Over Money
More than 40 states and the District of Columbia require private investigators to hold a license. Requirements vary but generally include a minimum age, relevant experience or education in criminal justice or a related field, a background check, fingerprinting, passing an examination, and carrying a surety bond. A few states have no licensing requirement at all, which puts the diligence entirely on you.
Hiring an unlicensed investigator in a state that requires licensing creates two problems. Any evidence gathered may be thrown out in court, which defeats the purpose if legal proceedings are involved. And you could face your own legal exposure if the unlicensed investigator violates privacy laws during the case.
Most state licensing agencies maintain online databases where you can search by name or license number. The agency responsible varies, but it is often the department of public safety, the department of licensing, or a bureau of security and investigative services. A licensed investigator will hand over their license number without hesitation. If someone resists, find someone else.
What the Service Agreement Should Cover
A written agreement protects both sides and prevents billing disputes. Read it carefully before signing, and push back on anything vague. At a minimum it should address:
- Scope of work. A specific description of what the investigator will and won’t do. “Conduct investigation” is not enough.
- Fee structure. Hourly, flat, or retainer, with the exact rate stated. If hourly, ask whether time is rounded to the nearest quarter-hour or half-hour. That detail affects the bill more than most clients realize.
- Expense policies. Which additional costs (mileage, databases, equipment) get passed through, at what rates, and whether they need your approval above a threshold.
- Reporting frequency. How often you’ll receive updates and in what form. Some investigators send weekly written summaries; others call only when there’s something significant.
- Deliverables. Whether a final written report is included, whether you’ll receive copies of photos or video, and the format for evidence handoff.
- Confidentiality. A clear statement that the investigator will protect your information and the details of the case.
- Termination terms. How either party can end the engagement, what notice is required, and how unused retainer funds are refunded.
Ask what happens if the retainer runs out mid-investigation. You want to know whether work stops until you replenish it or whether the investigator keeps going and bills you after the fact. Also ask what happens if the investigation turns up nothing. An experienced investigator will be straightforward: some cases don’t produce the answers the client hoped for, and you still owe for the time spent.
How to Keep the Bill Down
The single biggest thing you can do to control costs is show up prepared for the first meeting. Bring everything you already know: names, addresses, phone numbers, social media profiles, vehicle descriptions, dates, and any documents related to the situation. The more legwork you’ve done, the fewer billable hours the investigator spends gathering basics you could have handed over.
Be specific about your objectives. “I want to know if my business partner is stealing from the company” gives an investigator something concrete to work with. “Something feels off” does not. Vague instructions lead to open-ended investigations that run up costs without producing actionable results.
Ask for a realistic cost estimate before the investigation begins, with a best-case and worst-case range. No investigator can predict exactly what a case will cost, but an experienced one can give you a reasonable range based on similar cases. If the estimate exceeds your budget, a good investigator can often suggest a phased approach: tackle the highest-priority questions first and expand the scope only if the initial findings warrant it.