How to Start a PI Agency
Opening your own investigation business, starting with your state's licensing agency and ending with the first case you report on and bill.
This page covers opening a private investigation business: licensing questions for your state, registering, tax IDs and insurance, setting terms with the first client and sending the first invoice. Billing hours, mileage and outside costs is on the private investigator invoicing guide linked below.
The BLS private detectives and investigators profile (In the US, last modified October 29, 2026) says "Private detectives and investigators gather, analyze, and report information to clients regarding legal or personal matters." It also says "Private detectives and investigators must properly collect and document evidence so that it may be used in a court of law." For licensing, ask the agency in your state that licenses investigators before you take a paid case.
A first case invoice with sample figures: 6 hours of surveillance x $85.00 = $510.00 and a records search fee passed on at 1 x $45.00 come to $510.00 + $45.00 = $555.00 before any tax.
Step-by-step startup guide
Follow these steps to launch your private investigator business on solid footing.
- 1
Ask your state's licensing agency
Find out from the agency in your state that licenses investigators what it requires before you take paid cases.
- 2
Choose your case types
Background checks, surveillance or legal support work each need different tools and attract different clients.
- 3
Register and get an EIN
The SBA's launch guide (In the US, SBA, checked October 31, 2026) says "Your Employer Identification Number (EIN) is your business’s federal tax ID number." The IRS EIN page (In the US, IRS, last reviewed or updated October 16, 2026) says "You never have to pay a fee for an EIN."
- 4
Look into insurance
The SBA's launch guide (In the US, SBA, checked October 31, 2026) says "You also may be legally required to purchase certain types of business insurance." A licensed agent can talk you through cover for investigative work.
- 5
Put terms in writing
Set the scope, your hourly rate, how outside costs are billed and how you'll report, and have the client sign before work starts.
- 6
Report, then invoice
Deliver your report and invoice the hours and costs from the signed terms.
Tips for starting your private investigator business
- Document as you go. The BLS private detectives and investigators profile (In the US, last modified October 29, 2026) says "Private detectives and investigators must properly collect and document evidence so that it may be used in a court of law."
- Record your hours on each case the same day.
- Keep receipts for every outside cost you pass on to a client.
- Ask a lawyer about the legal limits on the methods you plan to use.
How Billed helps you get started
Features to look at as you set up your business.
Log Time
Billed's features page says: "Log time for your tasks quickly and easily and save time."
Hourly Rate Projects
Billed's features page says: "Manage hourly rate projects and track time for your projects."
Client Invoices
Billed's features page says: "See all of customer’s invoices in one place and save time."
Payments Report
Billed's features page says: "Get all the payment details in a specific period of time."
Frequently asked questions
Invoice Your First Case
Create invoices, track payments and keep your clients' details in one place with Billed.
At a glance
| Step | What to check | Source |
|---|---|---|
| License | Your state's licensing agency | State pointer |
| Evidence | Collect and document it properly | BLS (In the US, last modified October 29, 2026) |
| Tax ID | An EIN, at no fee | IRS (In the US, last reviewed or updated October 16, 2026) |
| First invoice | Hours and outside costs from the signed terms | Private investigator invoicing guide |
When this isn't for you
If you investigate as an employee of an agency, an insurer or a law firm, these setup steps won't apply to you.