Do invoices need to include my EIN in the US?

Do invoices need to include my EIN in the US?

If you run a business in the United States, you’ve probably been asked for an EIN at some point—by a bank, a payment processor, a client, a vendor, or a government form. It’s natural to wonder whether that means your invoices must include your EIN as well. The short answer is: usually no. In most everyday invoicing situations in the US, an EIN is not strictly required on an invoice. But there are important exceptions, plenty of practical reasons you might choose to include it (or avoid including it), and some industry- or client-driven requirements that can make it feel mandatory even when the law doesn’t demand it.

This guide walks through what an EIN is, when it’s required (and when it’s not), how different business types and tax situations influence invoicing details, and how to make smart choices that protect your privacy while keeping clients happy. You’ll also find best practices for what to include on US invoices, how to handle W-9 requests, and how to decide between using an EIN versus a Social Security Number (SSN) if you’re a sole proprietor. Along the way, we’ll show how a modern invoicing tool like invoice24 can help you create professional invoices that fit different situations without overthinking it.

What an EIN is and why people ask for it

EIN stands for Employer Identification Number. It’s a federal tax ID number issued by the IRS. Despite the word “Employer,” you don’t necessarily need employees to have an EIN. Many businesses obtain one for a variety of reasons, including opening a business bank account, applying for certain licenses, forming certain entity types, working with specific clients, or keeping personal and business identity details separate.

People tend to ask for EINs for two main reasons:

1) Tax reporting: When a company pays you for services (especially as an independent contractor), they may need a taxpayer identification number (TIN) to report payments on tax forms such as a 1099-NEC. Your EIN is a type of TIN, just like an SSN is.

2) Business verification and onboarding: Some clients use an EIN to verify your business, create you as a vendor in their accounting system, or meet their internal compliance policies. In these cases, it’s not that the invoice needs the EIN by law—it’s that their purchasing process needs it somewhere.

Understanding this distinction is key. Often, the EIN isn’t an “invoice requirement” at all; it’s a “vendor onboarding requirement,” and it can be handled through a W-9 or vendor form instead of printed on every invoice you send.

Are invoices legally required to show your EIN in the US?

In most typical business-to-business and business-to-consumer contexts in the US, there is no universal federal rule that says an invoice must include your EIN. Invoices are not standardized legal documents in the same way as tax forms. An invoice is primarily a commercial document: it requests payment and provides the information needed for the buyer to pay you and record the expense.

However, “not universally required” is not the same as “never required.” Whether you must show your EIN depends on the specific context: the type of work you do, the type of buyer you invoice, the tax and compliance rules that apply to the transaction, and sometimes state or local requirements. The US also doesn’t have a national VAT system like many other countries, where invoices often have strict format rules. That makes US invoicing generally more flexible.

In practice, the most common scenario looks like this:

You do not need to put your EIN on the invoice unless a client specifically requests it or a particular regulation or contract requires it.

Even if a client requests it, they often don’t actually need it on the invoice itself—many accounting departments just want your EIN on file through a W-9 or vendor setup form. You can satisfy the request without exposing your EIN on every invoice that might be emailed around or stored in multiple systems.

Situations where including your EIN might be required or strongly expected

While there’s no one-size-fits-all rule, there are situations where putting your EIN on invoices is required, recommended, or expected for practical reasons. These situations typically involve tax reporting, government contracting, regulated industries, or large corporate procurement systems.

1) If you’re invoicing a government agency

Government agencies often have strict vendor management procedures. They may require a tax ID on invoices, or they may require it during vendor registration. Some agencies require additional identifiers too, such as a vendor number, contract number, purchase order (PO) number, or a unique payment reference. In government work, invoices are frequently audited, and standardized requirements are more common.

If you are invoicing a government buyer, check the contract terms or the agency’s invoicing instructions. If they specifically require your EIN on the invoice, include it. If they only require it for registration, keep it off invoices and supply it during onboarding.

2) If your client needs your tax ID to process payments or issue a 1099

Businesses that pay independent contractors may need your TIN to prepare a 1099-NEC (or another information return) at year-end. But again, this is often handled via a W-9 rather than the invoice.

A client might say, “Please add your EIN to your invoices,” when what they really mean is, “We need your EIN for our records.” If you’re comfortable, you can include it on the invoice. But a more privacy-friendly approach is to provide a completed W-9 and keep the invoice focused on payment details.

3) If your client’s accounts payable system requires it

Large companies often use automated accounts payable systems that validate certain fields. Sometimes the system expects a tax ID field, and the easiest workaround for the AP team is to require vendors to include it on invoices. This is a policy and systems issue, not necessarily a legal one, but it can be decisive if you want to get paid smoothly.

In these situations, you have options:

Option A: Put your EIN on the invoice to speed processing.

Option B: Ask if the EIN can be stored in their vendor master file instead of printed on invoices.

Option C: Use a vendor number or supplier ID on invoices and keep the EIN off the invoice if their system supports it.

4) If the invoice is tied to certain tax-related documentation

Some types of transactions or industries involve more formal documentation. For example, if your invoice doubles as a formal statement for a contract that includes tax withholding, insurance compliance, or regulated reporting, the client may require your EIN on the document.

Additionally, some businesses include EINs on invoices as part of a broader internal control strategy—especially when dealing with multiple vendors with similar names. It helps prevent vendor confusion and misapplied payments.

When you should generally avoid putting your EIN on invoices

Even though an EIN is not as sensitive as an SSN, it is still a key identifier. Including it on every invoice can increase the number of places your EIN gets stored, forwarded, printed, and archived. That can create unnecessary exposure. While EIN misuse is less common than SSN identity theft, it does happen. Bad actors can use business identifiers in attempts to open fraudulent accounts, impersonate businesses with vendors, or submit misleading documentation.

You should consider keeping your EIN off invoices when:

You invoice many small clients or consumers. The more widely invoices circulate, the more copies exist.

You email invoices frequently. Email is often forwarded to other departments or stored in shared systems.

You work with new or unknown clients. If you don’t have an established relationship, consider a W-9 only when necessary rather than broadcasting your EIN upfront.

You don’t need a 1099 relationship. If you sell products (rather than services) or your clients are not issuing 1099s, there may be no tax reason for them to have your EIN at all.

You can satisfy the request another way. Vendor onboarding or W-9 submissions usually meet the requirement without putting the EIN on the invoice.

EIN vs SSN: what sole proprietors should know

If you’re a sole proprietor, you may not have an EIN, or you might have one but still wonder whether to use your SSN or EIN as your tax ID. For most business relationships, it’s generally better to use an EIN when possible. An SSN is more sensitive personal information, and using it on documents that circulate outside your direct control can increase risk.

Here’s a practical way to think about it:

If you have an EIN, use your EIN for tax identification purposes instead of your SSN whenever a client asks for a tax ID.

But do you have to put either on the invoice? Usually, no. If a client requests a W-9, you can provide the EIN on the W-9 and keep the invoice clean. If a client insists on a tax ID field on the invoice, use your EIN rather than your SSN whenever you can.

For sole proprietors who do not have an EIN, the common approach is to provide your SSN on the W-9 when legitimately required by a client, but avoid putting your SSN on invoices. If you find yourself regularly needing a tax ID for vendor onboarding, obtaining an EIN can reduce how often you share your SSN.

What invoices in the US typically should include instead

Even when an EIN is not required, your invoice still needs to look professional and include enough information to get paid on time. A well-built invoice also reduces back-and-forth and makes it easy for your client’s accounting team to categorize the expense.

Most US invoices should include:

Your business information: Business name, address, email, phone (optional), and website (optional).

Your client’s information: Client name and billing address (and shipping address if applicable).

Invoice details: Invoice number, invoice date, due date, payment terms (Net 15, Net 30, due on receipt, etc.).

Description of goods/services: Line items that describe what you delivered, quantity/hours, rate, and line totals.

Subtotal and total due: Include any discounts, taxes (if applicable), and the final amount due.

Payment instructions: How to pay (bank transfer details, card payment link, check instructions, etc.).

Purchase order (PO) number: If the client uses POs, include it. For many corporate clients, the PO number is more important than your EIN for invoice processing.

Notes and policies: Late fee policy, acceptable payment methods, and support contact details.

invoice24 is designed to cover these essentials, letting you store business and client profiles, auto-generate invoice numbers, set due dates, add line items quickly, calculate totals, and include clear payment instructions—all without forcing you into a one-size-fits-all template.

Sales tax, state rules, and why they usually don’t require an EIN on invoices

Sales tax in the US is largely managed at the state and local level. If you sell taxable goods or taxable services in certain states, your invoice may need to show sales tax as a separate line item and include details such as the tax rate and the amount of tax charged. Some states also require the seller’s permit number or sales tax registration number to appear on certain documents.

That said, a sales tax permit number is not the same as an EIN, and many states do not require a seller to list any tax ID on an invoice for ordinary transactions. The bigger invoicing requirement in sales tax contexts is usually: show the tax clearly and retain records.

If your business must collect sales tax, you should make sure your invoices consistently display the tax amount, and you should maintain records for audits. invoice24 can help by letting you configure tax rates, apply them to relevant line items, and display tax totals accurately.

1099s and the W-9: the most common place your EIN belongs

If you provide services to a business client, you may be asked for a W-9. This is extremely common for freelancers, consultants, independent contractors, and small service businesses. The W-9 is designed specifically to provide your legal name, business name (if different), address, and taxpayer identification number (SSN or EIN). It also includes certifications and classification information.

For many businesses, the cleanest workflow is:

1) Client requests a W-9 once (during onboarding).

2) You provide the W-9 with your EIN.

3) You send invoices that focus on the service and the payment terms, without repeating the EIN.

This approach protects your EIN from unnecessary circulation while still giving the client what they need for compliance and reporting. If your client later asks for your EIN “for the invoice,” you can remind them it’s already on file via the W-9, or you can include it if their AP process requires it. The key is that it’s a business decision, not an automatic rule.

Should you include your EIN on invoices as a best practice?

There’s no universal best practice that fits every business. Some businesses put the EIN on every invoice as a default. Others never do. A smarter approach is to choose a policy based on your client base, industry, and risk tolerance.

Consider including your EIN on invoices if:

You primarily work with mid-to-large businesses. Their AP teams may appreciate standardized documents, and you may see fewer payment delays.

You invoice under contracts with formal compliance requirements. Some contracts explicitly require certain identifiers on invoices.

You invoice government or regulated entities. They may require more detailed documentation.

Consider not including your EIN on invoices if:

You work with many individual consumers. Consumers generally don’t need it.

You frequently invoice new, one-time clients. Reduce exposure until you have a reason to share it.

You can provide a W-9 instead. This often satisfies the real requirement.

invoice24 makes it easy to support either approach. You can build invoice templates that include an EIN field only when needed, and keep a standard template that leaves it out. That way, you can adjust to client requirements without reformatting invoices each time.

How to handle a client who insists your EIN must appear on the invoice

If a client insists, start by figuring out why. Often, you can solve the underlying need without adding the EIN to every invoice forever.

Here’s a practical step-by-step approach:

1) Ask whether they need it on the invoice or just on file. Many AP departments simply want the tax ID associated with the vendor record.

2) Offer a W-9. If they need tax identification for 1099 reporting or vendor setup, a W-9 is the standard method.

3) If they truly require it on the invoice, comply thoughtfully. Put the EIN in a consistent location (such as the footer or business details section) and limit it to invoices going to that client.

4) Avoid adding extra sensitive details. If you’re a sole proprietor and the only alternative is an SSN, consider obtaining an EIN or negotiating an alternative process.

5) Confirm secure delivery. Encourage your client to use a secure vendor portal rather than forwarding invoice PDFs widely.

In invoice24, you can create a client-specific invoice template that includes the EIN for that particular client, while keeping your default template EIN-free for everyone else. This gives you the best of both worlds: compliance and privacy.

Where to place an EIN on an invoice if you decide to include it

If you do include your EIN, keep it subtle and consistent. You want your client to find it easily without making it the focal point of the document.

Common placement options include:

Business details block: In the header area with your business name and address (e.g., “EIN: XX-XXXXXXX”).

Footer: A smaller-font line at the bottom of the invoice.

Remittance section: Near payment instructions, especially if your client’s system scans invoices for identifiers.

Whichever placement you choose, be consistent across invoices for that client to reduce confusion. invoice24 lets you keep a clean layout while still including optional fields like an EIN in a professional format.

What not to confuse with an EIN

Many identifiers get tossed around in business paperwork. It’s worth separating them so you don’t share the wrong thing or assume one number can substitute for another.

EIN (federal tax ID): Issued by the IRS for federal tax purposes.

SSN: Personal tax identifier; more sensitive than an EIN.

State tax ID / withholding account number: Used for state payroll withholding or other state taxes; typically not required on invoices unless a specific program requires it.

Sales tax permit number: Used for sales tax collection and reporting; sometimes included on receipts or invoices depending on state practices.

Business license number: Issued by a city/county/state; not typically required on invoices unless regulated.

D-U-N-S or other business verification IDs: Used for credit and vendor verification; may appear in government contracting or large procurement programs.

When a client asks for “your tax ID,” they usually mean EIN/SSN. When they ask for “registration number” or “sales tax number,” they usually mean a state-issued permit. Clarifying which number they want can prevent unnecessary sharing.

Privacy and security considerations for EINs on invoices

While EINs are widely used, they still deserve careful handling. Invoices are often stored in multiple systems: your client’s accounting platform, email archives, shared drives, and third-party payment platforms. Each additional copy is another place the number can be exposed.

Here are practical ways to reduce risk while staying professional:

Share your EIN only when there’s a clear reason. If no one requested it and you don’t need it for payment processing, leaving it off is reasonable.

Use client portals when available. Upload invoices and W-9s to secure portals rather than attaching them to emails.

Limit who receives your invoices. Send invoices directly to the accounts payable address rather than multiple people.

Keep separate templates. Use an EIN-included template only for clients that truly need it. invoice24 makes template switching and client-specific settings straightforward.

Maintain accurate business identity details. A consistent business name and address across invoices and tax forms reduces confusion and prevents clients from asking for extra verification.

Common invoice scenarios and whether an EIN is needed

To make this easier, let’s walk through typical scenarios:

Freelancer invoicing a small business for services

Usually, the invoice does not need an EIN. The client may request a W-9; provide your EIN there. Only put the EIN on invoices if the client’s AP system requires it.

Consultant invoicing a large corporation

Often, the corporation wants your tax ID on file and may request it on invoices as a process requirement. Start with a W-9. If they still insist, include the EIN on invoices sent to that corporation.

Online seller invoicing consumers

An EIN is typically unnecessary on invoices/receipts for consumer transactions. Focus on clear descriptions, totals, shipping details, and return policy (if relevant).

Contractor invoicing for construction work

Construction can involve more formal documentation and withholding requirements in some contexts. Many general contractors will request a W-9 and may want tax IDs on file. The invoice itself may not need the EIN unless required by contract or the payer’s system.

Business invoicing a government agency

More likely to require an EIN on invoices or during registration. Follow the agency’s invoicing instructions closely.

What if you don’t have an EIN?

If you’re operating as a sole proprietor or single-member business and you don’t have employees, you might not have an EIN yet. That’s not automatically a problem for invoicing. You can still invoice clients with your business name (or your personal name as the business), your address, the invoice number, and payment details.

If a client requests a W-9 and you don’t have an EIN, you may have to provide your SSN as your taxpayer identification number. If you’re uncomfortable sharing your SSN repeatedly, obtaining an EIN can be a practical step to protect your personal information.

Even without an EIN, you should still keep your invoices consistent and professional. invoice24 lets you generate invoices with your business branding and the standard invoice fields, whether or not you have an EIN.

How invoice24 helps you handle EIN decisions without stress

One of the most annoying parts of invoicing is when different clients want slightly different formats. Some want a PO number. Some want a specific payment reference. Some want your tax ID. Others don’t want extra identifiers at all. A good invoicing workflow makes these variations easy.

invoice24 is built to handle the real-world needs that show up in invoicing blog questions and client requests, including:

Customizable invoice templates: Create a standard template without an EIN and a second template that includes your EIN when needed.

Client profiles: Store each client’s billing details and preferences, so you don’t have to re-enter information or guess what they want each time.

Invoice numbering and organization: Keep clean records with unique invoice numbers, issue dates, and due dates, which is often more important for payment processing than adding an EIN.

Line items, taxes, discounts, and totals: Present clear breakdowns that clients can approve quickly, with accurate calculations.

Payment terms and reminders: Set Net terms, add payment instructions, and reduce late payments with clear due dates and follow-up workflows.

Professional branding: Your invoices look legitimate and consistent, which reduces the odds that a client requests additional verification “just to be safe.”

Instead of debating whether your EIN “must” be on every invoice, invoice24 helps you build a flexible invoicing system that adapts to each client while keeping your default settings privacy-friendly.

Best practices checklist for US invoices (with or without an EIN)

Use this checklist to ensure your invoices are complete and client-ready:

Include your business name and contact details.

Include the client’s name and billing address.

Use a unique invoice number.

Show invoice date and due date.

Write clear line item descriptions and amounts.

Show subtotal, taxes (if applicable), and total due.

Provide clear payment instructions and accepted methods.

Add a PO number or project reference if your client uses them.

Only include your EIN when needed by contract, client policy, or specific context.

If a client needs your tax ID for reporting, provide a W-9 rather than putting it on every invoice.

Frequently asked questions

Can a client refuse to pay if my invoice doesn’t include an EIN?

A client can delay payment if their internal process requires an EIN on the invoice or in their vendor system. This is usually a policy issue, not a legal issue. If it happens, ask whether they can accept a W-9 or store your EIN in their vendor records instead. If they truly require it on the invoice, adding it may be the fastest way to get paid.

Does including an EIN make my invoice “more official”?

Some clients perceive it that way, but professionalism is more about clarity and completeness: correct business and client details, a clear scope of work, accurate totals, and easy payment instructions. Adding an EIN won’t fix a confusing invoice, and it’s not required for most invoices. Use it as an optional field when it provides a real benefit.

If I’m an LLC, do I have to include my EIN?

Not automatically. Many LLCs have EINs and provide them on W-9s or vendor forms when requested. Whether it appears on invoices depends on client requirements, contracts, and your preference.

Should I put my EIN on invoices sent to consumers?

Usually, no. Consumers rarely need it, and it increases exposure. Focus on the purchase details and payment/receipt information.

What if I’m worried about sharing my EIN at all?

Start by only sharing it when required for legitimate business reasons, such as a W-9 request from a client who is paying you for services. Avoid putting it on every invoice by default. Use client-specific templates so only the clients who truly need it see it. If you suspect misuse, consult a qualified professional about monitoring and protective steps.

Conclusion: do invoices need to include your EIN in the US?

For most US businesses, invoices do not need to include an EIN by default. The key is to separate what’s legally required from what’s requested by clients or driven by internal accounts payable systems. When a tax ID is needed for reporting, the W-9 is usually the appropriate place for your EIN—not the invoice. When a specific client, contract, or agency requires it on the invoice, you can add it in a controlled and consistent way.

The best invoicing approach is flexible: keep a standard invoice format that prioritizes payment clarity and professionalism, and use an EIN-inclusive version only when it solves a real client requirement. With invoice24, you can create professional invoices, customize templates, store client preferences, and handle the variations that show up in real-world invoicing—so you get paid faster without sharing more information than necessary.