Do You Need an EIN to Send Invoices? (When and How to Get One)

One of the most common questions new freelancers and small business owners ask is whether they need an Employer Identification Number (EIN) before they can start sending invoices. The short answer is: it depends on your business structure and who you are invoicing. In many cases, you can legally invoice clients using your Social Security Number, but there are compelling reasons to get an EIN regardless.

What Is an EIN and Why Does It Matter?

An Employer Identification Number is a nine-digit number assigned by the IRS to identify your business for tax purposes. Think of it as a Social Security Number for your business. The IRS uses it to track your business tax filings, and clients may use it to report payments they make to you on Form 1099.

Even if you are a sole proprietor with no employees, an EIN provides a layer of identity protection. Sharing your SSN on every invoice you send increases your exposure to identity theft. An EIN lets you keep your personal number private while still meeting tax reporting requirements.

When You Can Invoice Without an EIN

If you are a sole proprietor or single-member LLC with no employees, the IRS does not require you to have an EIN. You can use your Social Security Number on W-9 forms and invoices. Many freelancers operate this way for years without issue.

• You are a sole proprietor filing taxes under your personal name
• You have no employees and do not plan to hire any
• You do not have a Keogh plan or deal with certain types of trusts or estates
• You are invoicing domestic clients who only need your SSN for 1099 reporting

However, just because you can invoice without an EIN does not mean you should. Most accountants recommend getting one as soon as you start doing business, and the application process is free and takes only a few minutes.

When an EIN Is Required

Certain business structures and activities make an EIN mandatory. If any of the following apply to you, you must obtain an EIN before invoicing.

1. Your business is structured as a partnership, multi-member LLC, S-corp, or C-corp
2. You have employees or plan to hire employees
3. You withhold taxes on income paid to a non-resident alien
4. You have a Keogh retirement plan
5. You are involved with certain trusts, estates, real estate mortgage investment conduits, or nonprofit organizations
6. You file excise tax returns for alcohol, tobacco, or firearms

Additionally, many banks require an EIN to open a business checking account, and some clients — especially larger corporations — will not pay invoices that lack an EIN. Government contracts almost always require one.

How to Apply for an EIN (Step by Step)

Getting an EIN is free and straightforward. Do not pay a third-party service to do it for you — the IRS makes the process simple and accessible.

1. Visit the IRS website at irs.gov and navigate to the EIN application page
2. Determine your eligibility — you must have a valid Taxpayer Identification Number (SSN or ITIN)
3. Complete the online application during business hours (Monday through Friday, 7 a.m. to 10 p.m. Eastern Time)
4. Answer questions about your business structure, reason for applying, and expected number of employees
5. Submit the application and receive your EIN immediately upon completion
6. Save the confirmation letter — this is the only notification you will receive

The entire online process takes about 10 to 15 minutes. You can also apply by fax (Form SS-4, four-day turnaround) or by mail (four-to-six-week turnaround), but the online method is fastest.

Where to Display Your EIN on Invoices

Once you have an EIN, you should include it on your invoices in a clear and professional manner. Most businesses place it near the top of the invoice alongside their business name and contact information, or in the footer. InvoiceFold lets you add your EIN to your business profile so it automatically appears on every invoice you generate, saving you from manually entering it each time.

Best Practices for Displaying Tax IDs

• Label it clearly as "EIN" or "Tax ID" so the client knows what the number represents
• Never display your SSN on invoices if you have an EIN — use the EIN instead
• Include the EIN on your W-9 form when clients request one
• Keep a copy of your EIN confirmation letter in a secure location

EIN Considerations for International Invoicing

If you invoice international clients, your EIN is generally not required on the invoice itself. Foreign clients do not file 1099s with the IRS. However, having an EIN can still be beneficial for establishing credibility and for situations where foreign banks or payment processors request a tax identification number as part of their compliance procedures.

An EIN costs nothing, takes minutes to obtain, and adds a layer of professionalism and security to every invoice you send. There is virtually no reason not to get one.

Simplify Tax Compliance with InvoiceFold

Whether you use an EIN or SSN, InvoiceFold makes it easy to create compliant invoices that include all the tax information your clients need. Set up your tax details once in your business profile, and every invoice you create will automatically include the correct information. InvoiceFold also tracks payments and generates reports that simplify your year-end tax filing, helping you stay organized and audit-ready.

Getting an EIN is one of the simplest steps you can take to professionalize your invoicing. Pair it with a modern invoicing tool like InvoiceFold, and you will have a streamlined, secure workflow that impresses clients and satisfies the IRS.