How to Invoice a Company as a Freelancer (B2B Invoicing Guide 2026)

---

Invoicing a solo client who pays you personally is straightforward. Invoicing a company — especially a mid-size or enterprise one — comes with its own set of rules, and getting them wrong is one of the most common reasons freelancer invoices sit unpaid for weeks. This guide covers exactly what corporate clients expect, step by step.

Before You Start Work: What to Confirm

• Purchase order (PO) number — many companies won’t process an invoice without one; ask before your first invoice, not when it’s rejected
• The correct billing contact — often a different person or department (accounts payable) than the person who hired you
• Payment terms — Net 30, Net 45, and Net 60 are all common with larger companies; confirm this in writing before starting, ideally in your contract
• Invoice submission method — some companies require invoices through a vendor portal (like Coupa or Ariba) rather than email
• Their legal entity name — “Acme Marketing” the brand and “Acme Marketing Solutions LLC” the legal entity billing you might be different; use the exact legal name

What a B2B Invoice Must Include

Field	Why It Matters for B2B
Unique invoice number	Required for their AP system to log and track it
PO number (if issued)	Many AP departments will bounce invoices without one
Your business legal name & tax ID (EIN/UTR/ABN)	Required for their vendor records and year-end tax reporting (1099/CIS)
Itemized description of work	Vague line items (“Services rendered”) slow down approval
Payment terms & due date	State the exact date, not just “Net 30” — removes ambiguity
Bank details or payment link	Wire/ACH details for larger companies; a payment link for smaller ones

Understanding Corporate Payment Terms

Unlike individual clients who often pay on receipt, companies typically pay on a fixed cycle — commonly Net 30, sometimes Net 60 or even Net 90 for larger enterprises. This isn’t a red flag; it’s standard accounts payable process, and their AP team is usually processing hundreds of vendor invoices on the same schedule. For a full breakdown of what these terms mean and how to negotiate shorter ones, see our guide to Net 30 payment terms.

Sole Proprietor vs LLC/Ltd: Does It Matter for Invoicing?

You can invoice a company as a sole proprietor using your own name — there’s no legal requirement to form an LLC or Ltd first. That said, larger companies’ vendor onboarding sometimes runs more smoothly with a registered business name and tax ID, since it matches the format their AP systems expect. In the USA, you’ll typically be asked to submit a W-9 before your first payment; in the UK, expect a request for your UTR number for CIS/tax purposes if the work is construction-related.

Common Mistakes That Delay Payment

• Missing or wrong PO number — the single most common reason a corporate invoice gets rejected outright
• Sending the invoice to your day-to-day contact instead of AP — it may sit in their inbox for weeks before being forwarded
• Inconsistent invoice numbering — some AP systems flag duplicate or out-of-sequence numbers as errors
• No follow-up before the due date — a short check-in a few days before the invoice is due (confirming it’s in their system and on track) catches problems early

Frequently Asked Questions

Do I need a PO number for every company invoice?

Not every company uses purchase orders, but many mid-size and large ones do — always ask during onboarding rather than assuming. If they issue one, include it prominently on every invoice for that engagement.

What if the company doesn’t respond to my invoice?

Follow up with the accounts payable contact directly (not just the person who hired you) a few days after sending, and again a few days before the due date. Large companies process invoices in batches, so a lack of response doesn’t necessarily mean a problem — but it’s always worth confirming it was received and logged.

Should I charge a deposit when working with a large company?

It’s less common with established enterprise clients (who reliably pay on terms) but standard practice with newer or smaller companies. For long engagements, milestone-based invoicing throughout the project is safer than a single invoice at the end regardless of company size.

---

Final Thoughts

Invoicing a company is a process problem, not a chasing-payment problem — get the PO number, the right billing contact, and the correct submission method sorted before you start work, and most corporate invoices get paid on schedule without any friction. The freelancers who struggle with corporate clients are almost always the ones who skipped this setup step, not the ones who followed up too much.

Disclaimer: This article is for informational purposes only and does not constitute legal or tax advice. Consult a qualified accountant for guidance specific to your business structure. Affiliate links are present in this article.