Types of Invoices: All 12 Explained (and When to Use Each)

Every invoice does the same core job — request payment, document the transaction — but the version you send changes with the situation: billing before vs after the work, correcting a mistake, crossing a border, charging VAT. Using the wrong type isn't fatal, but it confuses accounts payable, delays payment, and occasionally has tax consequences.

Here are the 12 invoice types that cover essentially every situation, what makes each one different, and when to reach for it. If you're still on "what is an invoice, period" — start with the definition guide and come back.

The quick map

| Type | When it's used | Requests payment? | |---|---|---| | Standard invoice | Default — work done, payment due | Yes | | Proforma invoice | Before work/shipment — a preview | No | | Deposit invoice | Upfront portion before work starts | Yes | | Interim / milestone invoice | Mid-project, per phase | Yes | | Final invoice | Project close — remaining balance | Yes | | Recurring invoice | Repeating billing cycles | Yes | | Retainer invoice | Prepaid blocks of availability/work | Yes | | Timesheet (T&M) invoice | Hours × rate + materials | Yes | | Credit note | Reducing/refunding a prior invoice | No (negative) | | Debit note | Increasing a prior invoice | Yes (addition) | | Commercial invoice | International shipments — customs | Customs doc | | Tax / VAT invoice | Where VAT/GST rules apply | Yes |

Now each one, in the order you're likely to meet them.

1. Standard invoice

The default document: work delivered (or goods sold), payment requested, due date attached. In accounting terms this is the sales invoice — same document, seller's-ledger name. Every field it needs is covered in how to write an invoice, and you can see a filled-in one in the annotated invoice example. Everything else on this list is a variation of this document — same skeleton, different job.

2. Proforma invoice

A preview of the invoice, sent before work or shipment — "here's what the bill will look like." It's not a payment request, doesn't get an invoice number from your real sequence, and doesn't create a receivable in your books. Clients use it for internal approval or import paperwork. The full rules (and the traps) are in what is a proforma invoice.

Use when: the client needs the numbers before they can say yes — budget approval, customs pre-clearance, prepayment setup.

3. Deposit invoice

A real invoice for the upfront portion of a project — commonly 30–50% — issued before work starts. Unlike a proforma, it's a genuine payment request with a number in your sequence. The final invoice later credits the deposit against the total. Mechanics in deposit invoices.

Use when: new clients, large projects, or any work where starting unpaid is a risk you don't want.

4. Interim (milestone) invoice

Issued mid-project when billing is split across phases: "50% on design approval, 50% on launch." Each interim invoice bills one completed milestone, referencing the contract. This is how larger projects avoid the invoice-everything-at-the-end cash-flow cliff — the structure is covered in milestone billing, and the partial-payment variant in partial payment invoices.

Use when: projects longer than ~a month, or any engagement where you don't want all your revenue arriving after all your work.

5. Final invoice

The last invoice of a project: remaining balance, minus deposits and interim payments already made, plus any approved change orders. It should show the arithmetic — total contract value, less amounts already invoiced, equals balance due — so the client's AP can reconcile it without emailing you. The full close-out format, timing, and traps are in final invoices.

Use when: closing any project that had a deposit or interim billing.

6. Recurring invoice

The same invoice on a repeating schedule — monthly hosting, a subscription, ongoing bookkeeping. Amount and line items are usually identical each cycle; only the number and dates change. The win is automation: generate and send on schedule instead of rebuilding the document every month. Details in recurring invoices.

Use when: the billing is calendar-driven rather than event-driven.

7. Retainer invoice

Bills a prepaid block of work or availability — "20 hours/month" or "priority access, $2,000/month" — typically issued at the start of the period (you're reserving capacity, not billing completed work). How retainers differ from ordinary recurring billing, and how unused hours work, is in retainer invoices.

Use when: clients pay for guaranteed availability, not itemized output.

8. Timesheet (time and materials) invoice

Hours × rate, plus materials at cost or with agreed markup — the invoice mirrors a time log. Accuracy and verifiability are the whole game: dates, task descriptions, hour counts the client can check. The format is covered in time and materials invoices and the hour-tracking side in how to invoice for hours worked.

Use when: scope is open-ended and the contract bills actual time.

9. Credit note

The "negative invoice": issued to reduce or cancel an amount you previously invoiced — a refund, an overbilling correction, returned goods. It references the original invoice number and carries negative amounts (or is labeled as a credit). You never delete or edit a sent invoice; you correct it with a credit note — that's the audit-safe way, explained in credit notes and how to cancel an invoice.

Use when: anything on an already-sent invoice needs to go down.

10. Debit note

The mirror image: increases what's owed on a prior transaction — undercharged, extra costs surfaced, agreed price adjustment. Rarer than credit notes (usually you'd just issue an additional standard invoice), but standard in some B2B and cross-border flows. See debit notes.

Use when: an existing invoice needs to go up and the client's process expects a linked adjustment document rather than a fresh invoice.

11. Commercial invoice

A customs document for international goods shipments: it declares what's being shipped, its value, origin, and HS codes so border authorities can assess duties. It looks like an invoice but its primary audience is customs, not accounts payable — requirements are stricter and different. Full field list in commercial invoices.

Use when: physical goods cross a border. (Services sold internationally use a standard invoice — see invoicing international clients.)

12. Tax invoice (VAT/GST invoice)

In VAT/GST countries (UK, EU, Australia, India, and most of the world outside the US), a "tax invoice" is a legally defined document: registration numbers, tax rate per line, tax amount shown separately — because the buyer uses it to reclaim the tax. Getting the fields wrong can void the client's deduction. Requirements by country are in tax invoices; if you need the layout, there's a dedicated VAT invoice template.

Use when: you're registered for VAT/GST and the sale is taxable. US sales tax does not require a special invoice type — a standard invoice with a tax line is fine.

Adjacent documents that are NOT invoices

Three documents get mistaken for invoice types but do a different job:

• Quote / estimate — a price offer before any agreement. See quote vs invoice.
• Purchase order — the buyer's document authorizing the purchase; your invoice answers it. See purchase order vs invoice.
• Receipt — proof that payment happened, issued after money moves. See invoice vs receipt.

And one delivery-format note: e-invoicing isn't a type but a channel — structured digital invoices (increasingly legally mandated in the EU and Latin America) that any of the above types can travel through. See e-invoicing.

How to pick, in one sentence each

• Billing normally after work? Standard.
• Client needs numbers before committing? Proforma.
• Money before you start? Deposit invoice.
• Long project? Interim invoices per milestone, final invoice at the end.
• Same bill every month? Recurring (or retainer, if they're buying availability).
• Billing hours? Timesheet/T&M.
• Fixing a sent invoice? Credit note (down) or debit note (up).
• Goods across a border? Commercial invoice.
• VAT/GST-registered? Your standard invoice must be a tax invoice.

Whichever type you need, the fields and math are the same skeleton — the free invoice generator covers the common ones without new layouts each time.

FAQ

What is the most common type of invoice?

The standard invoice — work delivered, payment requested, due date attached. For most freelancers it's 90%+ of what they send; the other types handle timing (deposit, interim, recurring), corrections (credit/debit notes), and jurisdiction (tax, commercial).

What type of invoice should a freelancer use?

Standard invoices for project work, a deposit invoice upfront for new clients, and recurring or retainer invoices for ongoing arrangements. The decision points are in how to invoice a client.

Is a proforma invoice a real invoice?

No — it's a preview with no payment obligation and no place in your invoice sequence. It becomes "real" only when you issue the actual invoice. Treating proformas as real invoices double-counts revenue and confuses audits; see proforma invoices.

What's the difference between a credit note and a refund?

The credit note is the document; the refund is the money movement. You issue a credit note to correct the books whether you return cash or offset the amount against the client's next invoice.

Do invoice types have different legal requirements?

Mostly no — standard, deposit, interim, recurring, and retainer invoices are all legally the same document with different timing. The exceptions: tax/VAT invoices (legally defined fields where VAT applies) and commercial invoices (customs requirements).

Can one invoice be two types at once?

Constantly — a recurring invoice can also be a tax invoice; a final invoice can include T&M lines. "Type" describes the job and timing, not a rigid format. The fields flex; the skeleton (the 10 required fields) stays.