Can I invoice clients for work performed before registering a business in the US?

Can You Invoice Clients for Work Performed Before Registering a Business in the US?

If you did work for a client and only later decided to “make it official” by registering a business, you’re not alone. Many freelancers and new founders start by taking on a few projects, getting paid, and then realizing they should set up an LLC, corporation, or at least a formal sole proprietorship structure. That naturally leads to a practical question: can you invoice clients for work performed before registering a business in the US?

The short version is that, in many situations, yes—you can invoice for work you already performed, even if your business entity wasn’t registered at the time. But the details matter. What you call yourself on the invoice, how the contract was formed, whether the client requires a W-9 or vendor onboarding, what dates you use, and how you handle taxes can change the safest approach.

This article walks through the real-world rules and best practices: what’s legally possible, what clients typically accept, how different business structures affect invoicing, what to do if you formed an LLC after the work was done, and how to build invoices that look professional and help you get paid faster—using a free invoicing tool like invoice24.

Understanding What “Registering a Business” Means

In the US, “registering a business” can mean several different things, depending on how formal you want to be and what structure you choose. This is important because the answer to your invoicing question often depends on what kind of registration you’re talking about.

If you’re operating as a sole proprietor, you may not need to register a separate entity at all. A sole proprietorship can begin the moment you start doing business—there is no state formation document like there is for an LLC or corporation. However, you may still need permits, licenses, sales tax registration, or a DBA (“doing business as”) filing if you want to use a brand name that isn’t your legal name.

If you’re forming an LLC or corporation, registration usually means filing formation paperwork with a state. That entity generally comes into legal existence on the effective date of formation. Some states allow delayed effective dates, but the key point is that your LLC didn’t legally exist before it was formed.

Separately, you might register for an EIN (Employer Identification Number) with the IRS. An EIN is not the same as forming a company, but many clients want an EIN on your W-9 for vendor records.

So when someone asks, “Can I invoice before registering a business?” they may be talking about one or more of these steps: forming an entity, filing a DBA, getting an EIN, opening a business bank account, registering for taxes, or getting licenses. Invoicing is possible in all sorts of early-stage scenarios; the main challenge is aligning your invoice identity with the reality of who did the work.

Yes, You Can Invoice for Past Work—Here’s Why

An invoice is not a magical legal document that creates a business out of thin air. It’s a request for payment that records what was provided, when it was provided, and how much is owed. If you performed services, delivered work, and your client agreed to pay (in writing or through clear actions), you generally have the right to bill them—regardless of whether you had formed an LLC at the time.

Think of it this way: people do work as individuals all the time. Consultants, freelancers, gig workers, tutors, handymen, designers, and developers often start as individuals. If you did the work personally, you can invoice personally.

The most common situation is that you performed work as yourself (your legal name) and later created an LLC for future work. In that case, invoicing for the earlier work under your personal name is usually the cleanest and least confusing option.

Where it gets tricky is when you want the invoice to show the newly formed business name or when the client insists on paying only a registered business entity. Those cases are solvable too, but they require a bit more care.

What Name Should Appear on the Invoice?

The name on your invoice should match the party that provided the service and the party that is legally entitled to collect payment. Before your LLC existed, it couldn’t “provide the service” as an entity, because it wasn’t yet a legal person. You, as an individual, did the work.

That means one of the best practices is:

If the work was done before your LLC/corporation existed, invoice under your personal name (sole proprietor) unless you have a clear, documented assignment of the contract or the client explicitly agrees to pay your new entity for prior work.

In practical terms, invoicing as an individual often looks like this:

• Your legal name as the “From” party (e.g., “Jordan Taylor”)
• Optionally a business/trade name if you have a DBA (e.g., “Jordan Taylor d/b/a BrightWave Studio”)
• Your mailing address and contact details
• Your payment instructions
• Your invoice number and date

If you already formed an LLC and want to use that brand going forward, you can still do so on future invoices. But for past work, mixing identities can slow down payment if the client’s accounts payable team can’t match you to their vendor records.

Can You Use a Business Name Before It Was Registered?

Many people use a business name informally before they file anything. Using a name on a website, email signature, or invoice isn’t automatically illegal. The key is whether you are misrepresenting your status. Claiming you are “BrightWave Studio LLC” before the LLC exists is a problem. Using “BrightWave Studio” as a trade name can be fine, but state and local rules vary and some places require a DBA filing if you operate under a name that isn’t your legal name.

As a rule of thumb:

• If you are not an LLC yet, do not put “LLC” on the invoice.
• If you are not incorporated, do not put “Inc.” or “Corp.” on the invoice.
• If you want branding, use a trade name without entity suffixes and include your legal name somewhere on the invoice.

For example, an invoice header could show “BrightWave Studio” and in the legal line show “Provided by Jordan Taylor” or “Jordan Taylor (sole proprietor).” This keeps things honest while maintaining branding.

What If You Formed an LLC After the Work and Want the Client to Pay the LLC?

Sometimes you want the payment to go to your LLC for bookkeeping, liability separation, or because the client requires a business entity. This can work, but you should understand what you’re doing: you’re asking the client to pay a different party than the one that originally did the work.

To handle this cleanly, consider these approaches:

Approach 1: Invoice Personally for Past Work (Simplest)

You invoice under your legal name for the work performed before formation. The client pays you. If you want to move funds into the LLC afterward, you handle it as an owner contribution, reimbursement, or other appropriate accounting entry (how you do that depends on your structure and tax choices). This approach minimizes client friction.

Approach 2: Assign the Contract/Receivable to the LLC (More Formal)

You can document that you are assigning the right to collect payment to your LLC. In many cases, clients will accept this if you provide a short written notice or an assignment agreement and the client confirms they’ll pay the LLC. Some clients have strict vendor rules and will require vendor onboarding under the LLC anyway.

If you choose this route, make it explicit and get written acknowledgment from the client. Otherwise, the client might insist on paying the original contracting party to avoid paying the wrong entity.

Approach 3: Re-issue a New Contract or Amendment (Often Client-Friendly)

If the relationship is ongoing, you can amend the agreement so future work is performed by the LLC. For past work, you can keep billing personally, and then switch to the LLC for later invoices. This hybrid approach is common and keeps the paper trail clear.

How Clients Typically React (And Why Accounts Payable Matters)

Even when something is legally fine, clients can have internal systems that complicate payment. Larger companies often have a vendor onboarding process that includes:

• W-9 collection (to issue a 1099 later if applicable)
• A vendor profile that matches a legal name and taxpayer ID (SSN/ITIN or EIN)
• Banking details validation
• Purchase order requirements
• Invoice formatting rules and net payment terms

If you did work before forming a business and the client already has you in their system as an individual, changing the payee name midstream can trigger delays. Accounts payable teams may reject invoices that don’t match the vendor record exactly.

So the best strategy to get paid quickly is often the most straightforward: invoice the same way the relationship started, then transition to the new entity going forward once you’ve completed onboarding.

What Dates Should You Use on the Invoice?

An invoice has multiple dates. Confusing these can create misunderstandings or even red flags. The main ones are:

• Invoice date: the date you issue the invoice (today’s date).
• Service date(s): the date range when the work was performed.
• Due date: when payment is due under your terms (e.g., Net 15, Net 30, due on receipt).
• Delivery/milestone date: optional, if you want to show when something was delivered.

For past work, it’s normal for the service date range to be earlier than the invoice date. For example, you may invoice on February 10 for services performed January 5–January 31. That’s common in consulting and monthly billing arrangements.

Be careful not to backdate the invoice date just to make it look “older.” You can be transparent and professional by showing the real service dates and the real invoice date.

Do You Need an EIN to Invoice?

You do not need an EIN simply to send an invoice. Individuals can invoice using their legal name and be paid by check, ACH, or card. That said, clients may request a W-9 and prefer an EIN rather than your Social Security Number.

If privacy is a concern, getting an EIN can be a practical step even as a sole proprietor. You can often obtain an EIN without forming an LLC, and then use that EIN on your W-9 and invoices if the client requests it.

However, do not confuse EIN issuance with business formation. An EIN is a federal tax identifier; an LLC is a state law entity. You can have one without the other.

Taxes: What Happens When You Bill for Work Done Before Formation?

Tax treatment depends primarily on when you earned the income and under what structure, not when you invoiced. In general, if you performed the work, received payment, or otherwise earned the income before forming an entity, it’s still taxable income. The question becomes: taxable to whom?

For most people, pre-formation income is personal income (sole proprietor income). If you later form an LLC that is treated as a disregarded entity for tax purposes (common for single-member LLCs), the tax outcome may be similar because the IRS treats that LLC’s income as your income anyway. But if your LLC is taxed as an S corporation or C corporation, timing and payroll considerations can become more complex.

Also note the difference between cash-basis and accrual-basis accounting. Many small businesses and freelancers use cash basis, meaning income is recognized when payment is received, not when the invoice is sent. Some businesses use accrual basis, meaning income is recognized when earned/invoiced, even if not yet paid. The accounting method you use affects how you track your books and taxes.

The safest and simplest mindset is this: keep clear records of what you did, when you did it, what you charged, and when you got paid. The invoice is part of that record.

Licenses, Permits, and Professional Requirements

Invoicing is one thing; legally performing certain kinds of work is another. Some industries and services require licenses at the state or local level, such as certain construction trades, real estate services, legal services, medical services, and other regulated professions. If your work was in a regulated field and you performed it without required licensing, the issue isn’t about whether you can invoice—it’s about whether the work was legally performed and enforceable.

Most freelance digital services (design, writing, marketing, software development, consulting) are not regulated in that way, but it’s worth making sure your specific service type doesn’t have special rules in your jurisdiction.

What If the Client Already Paid You Informally?

Sometimes a client pays you via Zelle, PayPal, Venmo, cash, or a quick bank transfer before you ever sent a formal invoice. If you want your records to look professional (and to make tax time easier), you can still create an invoice afterward and mark it as paid.

This can be useful for:

• Creating a consistent audit trail of services and payments
• Matching deposits in your bank account to specific projects
• Providing the client with a receipt-style document if they request one
• Improving your own bookkeeping and reporting

In invoice24, you can generate an invoice with accurate service dates, record the payment date and method, and keep everything organized without scrambling later.

How to Write a Clear Invoice for Work Done Before You Registered

Clients pay faster when invoices are clear, complete, and easy to approve. For past work, clarity matters even more because the dates don’t match “this week.” Here’s what a strong invoice should include:

1) Your identity
Use your legal name (and optionally your trade name). Include your address and email.

2) Client identity
Correct legal/business name, billing address, and the right contact or department.

3) Invoice number
Use a unique invoice number. A consistent numbering format looks professional and helps both sides track payments.

4) Invoice date and due date
Make terms explicit: “Due on receipt,” “Net 15,” “Net 30,” etc.

5) Service dates
Include a date range or specific milestone dates: “Services performed January 5–January 31.”

6) Line items with descriptions
Avoid vague labels like “work” or “services.” Use descriptions that match the contract or scope: “Website homepage design – 10 hours” or “Backend API integration – milestone 2.”

7) Totals, taxes (if applicable), and discounts
If you must charge sales tax (more common for certain goods and some services in some states), show it clearly. Many service-only invoices have no sales tax, but rules vary.

8) Payment methods and instructions
Include bank transfer info, card payment options, or other accepted methods. The easier you make payment, the faster you get paid.

9) Notes and references
Add a purchase order number, project name, or contract reference if the client uses one.

Invoice24 is built to help you include all of these elements quickly—especially helpful when you’re catching up on invoicing after realizing you need better systems.

Handling “LLC Pending” or “Business Registration in Progress”

Some people try to put “LLC pending” on invoices. In general, that’s not a great idea. It can confuse clients and raise questions you don’t want, like whether your invoice is valid or whether payment should be delayed until the entity exists.

Instead, invoice under the name that is currently valid. If you later form the LLC, you can communicate clearly:

• “For invoices dated after [formation date], please pay [LLC name].”
• “For prior invoices, please continue paying [your legal name].”

Clear transitions avoid rejected invoices and reduce back-and-forth with accounting teams.

What About Expenses You Paid Before Registering?

If you incurred project expenses before forming a business—like software subscriptions, travel, equipment, or contractor costs—you may still be able to treat them as business-related expenses, depending on your situation. The key is documentation and proper categorization. Keep receipts, note what project the expense relates to, and track it in your bookkeeping.

From a billing standpoint, if your agreement allows reimbursable expenses, you can invoice the client for those expenses even if you paid them before registration, as long as the expense was legitimate, within scope, and agreed upon. List reimbursements as separate line items with dates and descriptions.

Many clients prefer expenses to be clearly separated from services, which invoice24 supports through itemized line items and optional attachments (where appropriate).

Common Scenarios and the Best Way to Invoice

Scenario A: Freelance work with no formal business yet

You did the work as yourself, you have email proof of scope and pricing, and the client expects an invoice. Invoice under your legal name, include service dates, and send it. This is normal.

Scenario B: You formed an LLC after the work but before invoicing

If the work was performed before the LLC existed, invoice personally for that work, then start invoicing under the LLC for future work. If you insist on using the LLC, get client agreement and ensure their vendor record matches the LLC.

Scenario C: The client requires an EIN and W-9

Provide a W-9. If you don’t have an EIN, you may use your SSN/ITIN, but many prefer to obtain an EIN for privacy. Your invoice can still be issued under your legal name.

Scenario D: You used a brand name on emails and proposals, but never filed a DBA

Invoice using your legal name, and optionally reference the brand name as a trade name. Avoid using “LLC” unless you truly are one.

Scenario E: Ongoing contract spanning before and after LLC formation

Invoice pre-formation work personally up to the formation date, then invoice post-formation work under the LLC. If needed, use a contract amendment for the switch.

How to Avoid Disputes When Billing Retroactively

When invoicing for work already completed, the risk is not usually legality—it’s confusion and disputes. Here’s how to reduce that risk:

Be explicit about the service period. Clients rarely object when they can see exactly what time period the invoice covers.

Match the invoice to the agreement. Use the same project name, milestone labels, or hourly rate that was agreed.

Include supporting detail without overloading. A few strong line items beat a single vague one. If the client needs more detail, you can attach a timesheet or summary.

Send the invoice to the right person. For companies, that might be AP@company, a billing portal, or a finance contact, not just your day-to-day project stakeholder.

State your payment terms clearly. If you never discussed terms, “Due on receipt” is common for smaller clients, while larger clients often default to Net 30.

Follow up professionally. A friendly reminder after the due date is often all it takes.

Invoice24 supports recurring invoices, payment tracking, reminders, and organized client records so you can follow up without losing context.

Can a Client Refuse to Pay Because You Weren’t Registered Yet?

A client can refuse to pay for many reasons, but “you weren’t registered” is not automatically a valid reason if you actually performed the work and they accepted it. If you contracted and delivered, you generally have a right to payment. However, real life includes power dynamics: some clients may use any excuse to delay or avoid payment, and some companies have internal policies that restrict who they can pay.

That’s why vendor onboarding and clear paperwork can matter. If you’re working with larger organizations, they may require a W-9, a vendor profile, and sometimes proof of insurance before releasing funds. If you didn’t provide those upfront, they may pause payment until you do.

The solution is usually administrative rather than legal: provide the requested forms, ensure the invoice matches the vendor record, and keep communication calm and documented.

Professional Tips for Transitioning From “Individual” to “Business”

If you’re turning a side hustle into a real operation, you’ll eventually want consistency. Here are practical steps to make the transition smooth:

1) Decide your invoicing identity for past vs future work.
Draw a clean line: “Invoices before [date] are from me personally; invoices after are from the LLC.”

2) Standardize your invoice template.
Consistent formatting builds trust. Use your logo, clear contact info, and structured line items.

3) Keep numbering consistent.
Even if you switch entities, keeping a logical numbering system helps you track invoices. You can include a prefix to distinguish if needed.

4) Separate finances as soon as practical.
Open a dedicated bank account for the business if you formed an entity. Keep personal and business funds distinct going forward.

5) Update your contracts and proposals.
If you’re now operating as an LLC, ensure new agreements name the LLC as the service provider.

6) Collect the right client info early.
Billing address, AP email, PO requirements, and payment terms should be gathered before work starts.

7) Use an invoicing system from day one.
Even if you’re small, having invoices, payment tracking, and client history in one place saves time and reduces errors.

Invoice24 is designed for exactly this stage: you want something free, fast, and professional that still supports the features you’d expect from a serious invoicing workflow.

What to Put in the Invoice Notes for Pre-Registration Work

Most of the time, you don’t need to explain anything. You can simply list the services and dates and request payment. If you think the client might be confused, a short, neutral note can help:

• “Invoice for services performed between [start date] and [end date].”
• “Thank you—please include invoice number on payment reference.”
• “If you require a W-9 for processing, please let me know.”

Avoid long explanations about registration timelines. Keep the invoice focused on the transaction.

Key Takeaways

You can generally invoice US clients for work performed before registering a business. The bigger challenge is not whether you’re allowed to invoice—it’s choosing the right identity on the invoice and keeping things consistent with what the client expects.

For most freelancers and early-stage founders, the cleanest approach is to invoice under your legal name for pre-formation work, then invoice under your new LLC or corporation for work performed after formation. If you want a client to pay the LLC for earlier work, get written agreement and make sure their vendor record matches.

Make your invoices clear: include service dates, detailed line items, payment terms, and easy payment instructions. A professional invoice reduces questions, prevents delays, and strengthens client trust—especially when you’re catching up on work done earlier.

Whether you’re sending your first retroactive invoice or building a reliable invoicing process for the long term, invoice24 can help you create clean, branded invoices, track payments, send reminders, and keep everything organized—without adding cost or complexity.

Final Practical Checklist Before You Send the Invoice

Before sending your invoice for work performed prior to business registration, quickly check:

• Does the “From” name match who did the work (you personally vs your entity)?
• Are service dates clearly shown and accurate?
• Do line items match the agreed scope or milestones?
• Are the client’s billing details and contact correct?
• Did you include a unique invoice number, invoice date, and due date?
• Are payment methods and instructions clear and easy?
• If the client needs a W-9, are you ready to provide it promptly?

Send it, keep it professional, and follow up calmly if payment is late. In most cases, invoicing for pre-registration work is routine—and with the right structure, it can be just as smooth as any other invoice you send.