Invoicing a company as an individual is straightforward once you know what they need. The main difference from invoicing a small business owner is that larger companies have formal accounts payable processes — and your invoice has to fit their system to get paid on time.
What to include on your invoice
Your legal name and address. Use your full legal name, or your trading/business name if you have one. Include your address — companies need this for their vendor records and for any tax documents they issue you (W-9 in the US, equivalent in other countries).
Invoice number. Every invoice should have a unique number. Start with 001 or 1001 and increment from there. Companies track invoices by number for their accounts payable process — if you send an invoice without a number, it may bounce back to you.
Invoice date and due date. The invoice date is when you issued it. The due date is when payment is expected. For corporate clients, Net 30 is the typical standard — though you can try Net 14 for smaller companies.
Description of services. Be specific. “Web design — [project name]” is better than “Design services.” Line items with descriptions reduce back-and-forth with accounts payable and prevent “what is this for?” questions that delay payment.
Amount. Itemize if you billed for multiple deliverables or a mix of time and expenses. A single total is fine for a flat-rate project.
Your payment details. Include your bank account details for ACH/wire transfers, or your preferred payment method (PayPal, Stripe payment link, check instructions). Companies can’t pay you if they don’t know how.
Tax ID (if required). In the US, this is your Social Security Number or EIN. Many companies won’t process payment to a new vendor without a completed W-9 form. Ask your contact whether you need to submit one before sending your first invoice.
What large companies often add
If your client is a mid-size or large company, they may have additional requirements:
Purchase order (PO) number. Many companies require their own PO number on your invoice to route it through their approval system. Ask your contact: “Do I need a PO number for my invoice?” before you send it. If yes, they’ll provide one. Without it, the invoice may sit in a queue waiting for approval.
Billing contact. Some companies have a specific accounts payable email address that’s different from your day-to-day contact. Find out where to send the invoice — sending to the wrong person can add weeks of delay.
Vendor registration. Larger companies sometimes require you to register as a vendor in their procurement system before they can process a payment. This is a one-time setup and usually takes less than 30 minutes.
Payment terms for corporate clients
Net 30 is the standard expectation for corporate invoices. Some companies have Net 45 or Net 60 as default, particularly in industries like advertising or construction where long payment cycles are common.
If you’re accustomed to Net 14 or faster payment from small business clients, be prepared for corporate clients to take the full 30 days — or more. Build this into your cash flow planning. If Net 30 doesn’t work for you, say so upfront during the contract discussion rather than after you’ve sent the invoice.
You can include a late payment clause: “Invoices unpaid after [due date] are subject to a 1.5% monthly service charge.” Whether you enforce it is your call, but having it on the invoice signals that you track payment timing.
Using a professional invoice tool
Even as an individual, your invoice should look professional. A PDF generated from Waco3 or a similar invoicing tool — with a clean layout, consistent numbering, and all required fields — looks more credible than a Word document or a spreadsheet. Companies that process hundreds of invoices a month respond faster to invoices that are easy to route through their system.
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