Which documents does a freelancer need to issue?

Mainly a quotation (before work), an invoice (to request payment), and a receipt (once paid). The 50 Bis withholding certificate is something you receive from corporate clients, not something you issue.

Is an invoice different from a billing note?

They serve the same purpose — requesting payment. A "billing note" is common with corporate clients that run payment cycles and need it submitted for their finance team, while "invoice" is the more general term.

Are a receipt and a tax invoice the same?

No. A receipt is proof of payment that anyone can issue, while a tax invoice can be issued only by a VAT-registered person. If you are not VAT-registered, you can issue only a receipt.

Why keep the 50 Bis certificate?

Because the tax your client withheld (often 3%) is income tax paid in advance. You use the 50 Bis to credit it back on your annual return — if you do not keep them, you may lose that credit.

Getting-started guide for freelancers

The documents a freelancer needs to get paid

New freelancers often get confused about which documents to issue. The short answer: there are four key documents that follow the flow of a job — quotation → invoice → receipt — plus one you receive from corporate clients: the withholding-tax certificate (50 Bis).

By the BillsOS team · Updated 7 Jun 2026

Overview: which document, when

Stage	Document	Who issues it
1. Before the work	Quotation	You → client
2. Requesting payment	Invoice / billing note	You → client
3. After payment	Receipt	You → client
4. Tax withheld	50 Bis certificate	Company client → you

1. Quotation

Issued before the work starts, to propose the price and scope for the client to approve. It gets both sides aligned on price, terms, and delivery before any work begins — and heads off money disputes later.

Should include: your name and the client, line items and prices, any applicable tax, and a price-valid-until date.

2. Invoice / Billing note

Issued when payment is due — on delivery, or per the agreed milestones. The invoice states the amount due and the due date. For convenience, attach a payment method such as a PromptPay QR pre-filled with the exact amount.

A "billing note" (ใบวางบิล) is common with corporate clients that run payment cycles — you submit it for their finance team to schedule payment. "Invoice" is the more general term. Both serve the same purpose: requesting payment.

3. Receipt

Issued after you receive payment, to confirm it. It is important proof of income for your annual tax return. An individual freelancer can issue a receipt normally, using your name and 13-digit national ID.

Note: a receipt is not the same as a tax invoice. If you are not VAT-registered, you can issue only a receipt, not a tax invoice. Read more

4. The 50 Bis withholding-tax certificate

This one you receive rather than issue. When a corporate client pays a freelancer, it usually withholds tax at source (commonly 3% for general services) and gives you a 50 Bis certificate as proof.

Never throw away a 50 Bis certificate — the tax withheld is income tax paid in advance, which you credit back when you file your annual return. If you do not keep them all, you may lose that credit.

Individual freelancer vs. a company

An individual can issue quotations, invoices, and receipts without registering a company.
A tax invoice (7% VAT) can be issued only once you are VAT-registered, which is mandatory above THB 1.8M income per year.
Whether or not you register for VAT, every freelancer must file annual personal income tax.

Issue all of them in one place with BillsOS

BillsOS handles the whole cycle in one tool — issue a quotation, convert it to an invoice, attach a PromptPay QR pre-filled with the exact amount, then issue a receipt once paid. If you are the payer who must withhold tax, you can issue the 50 Bis too. All bilingual Thai/English, with customer history kept automatically.

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Information as reviewed on 7 Jun 2026. General information, not specific tax advice — verify with the Revenue Department (hotline 1161) or your accountant before relying on it.