How Much Does a Private Investigator Cost in the UK?

Private investigator costs in the UK vary significantly depending on the investigation type, location, and the firm's experience. As of 2025, expect to pay £50 to £150 per hour for standard investigations, with daily retainers ranging from £400 to £1,200. This article breaks down real UK pricing, what affects your final bill, and how to get value for money without overpaying.

UK Private Investigator Hourly Rates: What You'll Actually Pay

Most UK private investigators charge between £70 and £120 per hour, though London and the South East tend to be at the higher end of this range. Trainee or newly qualified investigators may charge £40–£60 per hour, while specialist firms (fraud, corporate, infidelity) often exceed £130 per hour.

What's included in the hourly rate varies. Some charge for all time spent on your case—interview time, research, surveillance, report writing, travel, and administration. Others cap travel time or charge it separately. Always ask for clarity on what the hourly rate covers before committing.

Location matters significantly. London investigators can charge 20–30% more than those in Manchester, Birmingham, or rural areas. A £100/hour rate in central London might be £70–£80 in the Midlands or North.

Daily Rates vs Hourly Rates: Which Costs Less?

Many UK private investigators offer daily rates as an alternative to hourly billing. A daily rate typically covers 8 hours of work and costs between £400 and £1,200, depending on the investigator's experience and location. This works out at £50–£150 per hour, so it's broadly equivalent to hourly rates but offers better value if your investigation requires extended surveillance or fieldwork.

Daily rates work best for:

• Surveillance operations (following a person for a full day)
• Pre-litigation investigations requiring extended observation
• Background checks involving multiple location visits
• Corporate due diligence that spans several days

Investigations lasting 3+ days often qualify for discounts. Many firms offer 10–15% reductions on daily rates for multi-day jobs. Always negotiate if your case requires sustained work.

Initial Consultation and Retainer Fees

Most UK private investigators charge a consultation fee to assess your case, typically £50–£150 for 30–60 minutes. This fee is usually non-refundable but may be deducted from your first invoice if you proceed. Some firms offer free initial consultations, though this is less common among experienced operators.

Once you instruct an investigator, you'll typically pay an upfront retainer. Retainers usually range from £500 to £2,000, depending on the case type and expected workload. This acts as a prepayment for future work; the investigator bills against this balance and invoices you when it runs low. Unused retainer is often refundable, though terms vary—check before paying.

Retainers protect the investigator from clients who disappear mid-investigation and give you certainty that funds are available to complete the work.

Investigation Type and Specific Costs

Different investigation types carry different price tags.

Infidelity and Personal Investigations

Cost: £70–£120 per hour or £500–£900 per day. These often involve surveillance of a spouse or partner. Pricing depends on how many hours of observation are needed and whether evidence must be documented for legal proceedings. Evidence-grade surveillance (admissible in court) may cost more due to higher standards of documentation.

Background Checks and Due Diligence

Cost: £300–£1,000 per subject. Corporate or personal background checks are often priced as flat fees rather than hourly. Checks involving multiple databases, international records, or financial history cost more. A simple UK address history check might be £200–£400; a full corporate due diligence report can reach £2,000–£5,000.

Fraud and Financial Investigation

Cost: £100–£150 per hour or £1,000–£2,000+ per day. These are specialist roles requiring accountancy knowledge or forensic expertise. Expect higher rates and longer investigation periods. Insurance fraud cases may be partly or fully funded by your insurer—always ask if they'll contribute.

Workplace and Employee Investigations

Cost: £60–£110 per hour or £600–£1,200 per day. These suit employers investigating misconduct, theft, or policy breaches. Some firms offer fixed-fee packages for routine cases (for example, £1,500–£2,500 for a standard disciplinary investigation).

Missing Persons

Cost: £50–£100 per hour or £400–£1,000 per day. These often require longer timeframes and networking with other specialists. UK tracing agents may charge fixed fees (£200–£500) for simple address tracing; complex missing persons cases can run into thousands.

Hidden Costs and Expenses to Watch For

The hourly or daily rate is not the full picture. Private investigators pass on legitimate expenses, and these can add significantly to your bill.

Common expenses include:

• Travel: Petrol, train fares, hotels for out-of-area work. Sometimes charged at cost; sometimes at £0.45 per mile. Request a cap before work starts.
• Database access fees: Credit reference checks, public records searches, and specialist databases cost £10–£150 each. The investigator may pass these on directly.
• Technical equipment: GPS tracking, camera hire, or specialist surveillance gear may be charged as items or daily hire fees.
• Witness interviews and third-party inquiries: May attract additional fees if they require specialist expertise such as solicitor review or expert witness consultation.
• Report writing and legal preparation: Detailed court-ready reports cost more than basic summaries—expect £200–£500 extra for expert formatting.
• Postage, copying, and administration: Small but cumulative—typically £50–£200 per investigation.

Always request a full breakdown of what costs are included in the hourly rate and what will be charged separately. This prevents invoice shock at the end of the case.

How to Avoid Overpaying for a Private Investigator

The UK private investigation market is largely unregulated, with no statutory body setting minimum charges or enforcing standards. Prices vary significantly, and some firms overcharge. Here's how to pay fairly:

Get Multiple Quotes

Contact at least three investigators and compare hourly rates, retainer sizes, and what's included. Don't automatically choose the cheapest—a £50/hour investigator may be inexperienced or cut corners. A £120/hour investigator with a strong track record may deliver better value.

Check Credentials and Experience

Ask if the investigator is a member of the National Association of Private Investigators (NAPI), the Association of British Investigators (ABI), or equivalent. While membership doesn't guarantee quality, it indicates professional standards. Request references from previous clients (subject to confidentiality).

Clarify the Scope and Timeline

Vague investigations can spiral in cost. A clear brief—"track movements between 9am–5pm on these three dates"—is cheaper than "find out what they're up to." Ask the investigator to estimate hours needed and set a budget cap. Many will stop work if costs approach your limit.

Negotiate Discounts for Longer Work

If your case requires 5+ days of investigation, ask for a daily rate reduction (10–15% is reasonable). Multi-week cases sometimes qualify for weekly discounts.

Avoid Upfront Large Payments

Never pay the full estimated cost upfront. Pay the retainer (usually refundable) and agree to invoice-as-you-go terms. Reputable firms will accept this.

When to Use a Cheaper Investigator (And When Not To)

Budget investigators work fine for straightforward cases: basic background checks, missing persons traces, or simple address verification. The work is low-risk and doesn't require courtroom standards.

Avoid budget investigators for:

• Legal cases where evidence must be admissible in court
• High-value disputes (over £10,000)
• Cases involving fraud, crime, or sensitive allegations
• Corporate due diligence on major acquisitions

Court-ready evidence requires expertise. A cheap investigation conducted improperly can be rejected by the court, wasting your money entirely. For litigation, spend £100–£150/hour on a qualified, accredited investigator. It's cheaper than losing a court case.

Frequently Asked Questions

How long does a typical private investigation take?

Simple cases (address checks, basic background) take 2–10 hours (1–3 days). Infidelity investigations average 20–50 hours over 2–4 weeks. Complex fraud or corporate cases can exceed 100 hours over several months. Your investigator should estimate timescales during the initial consultation.

Can I claim private investigator costs against tax?

If the investigation is for a business purpose (employee misconduct, fraud, commercial dispute), costs are usually tax-deductible as a business expense. Personal cases (infidelity, child custody) are not. Consult your accountant or tax advisor for your specific situation.

Do private investigators need a licence in the UK?

Private investigators don't require a specific "investigator's licence" in the UK, but they may need a Security Industry Authority (SIA) licence if they carry out certain security-related activities. Always ask to see credentials and verify them with the SIA if claimed.

What's the difference between a private investigator and a solicitor?

Solicitors provide legal advice and can represent you in court; private investigators gather evidence and information. For legal disputes, solicitors often hire private investigators on your behalf. Investigators cannot give legal advice but often work faster and cheaper than lawyers for fact-finding.

Will a private investigator disclose their sources or methods?

Usually no. Investigators protect their sources and methods to ensure future cases aren't compromised. However, for court cases, they may need to disclose methods to demonstrate evidence was obtained legally. Discuss confidentiality and legal disclosure requirements upfront.