Quotation, Invoice, Receipt: How the Thai Business Document Flow Works

Quotation → Invoice → Receipt: The Basic Flow

Do business in Thailand for long enough and you'll run into the same sequence of documents again and again: a quotation to agree the price, sometimes an order confirmation once the client accepts, an invoice once the work is billable, and a receipt once you've been paid. Each one serves a different purpose, and mixing them up — sending an "invoice" when you mean a quote, for example — creates confusion for your client and your accountant alike.

The Quotation: Agreeing the Price First

A quotation (ใบเสนอราคา) sets out what you're proposing to deliver and at what price, before any invoice exists. It's not a demand for payment — it's a proposal your client can accept, negotiate, or decline. For work where the scope or price needs sign-off first, a clean, numbered quotation avoids any ambiguity about what was actually agreed.

The Order Confirmation: Locking In What Was Agreed

Once a client accepts a quotation, an order confirmation records exactly what was agreed — the same line items and price, now confirmed rather than proposed. It's a useful middle step for larger orders or projects, giving both sides a clear record before an invoice is issued.

The Invoice: The Actual Bill

The invoice is where a payment obligation is created. It states what's owed, when it's due, and the VAT treatment per line item — net, VAT, and gross calculated automatically. This is the document your client's accounts team works from, and the one you'll reference if you need to follow up on a payment.

The Receipt: Proof of Payment

Once an invoice is paid — in full or in part — a receipt (ใบเสร็จรับเงิน) confirms the payment was received. For Thai clients, this is also where withholding tax shows up: if the customer is based in Thailand, Lemon Invoice automatically flags them for the standard 3% withholding tax, calculated on the net amount, and shows it on the receipt — so the amount you actually received and the amount on your receipt agree, instead of leaving a gap to explain later.

Converting Between Documents Without Retyping

In Lemon Invoice, this isn't four separate documents built from scratch — it's one flow. Turn a quotation into an invoice, and an invoice into a receipt, without retyping the client's details or line items each time. That matters most when a quotation needs revising or a project runs across several invoices: everything traces back to the same source instead of drifting apart.

Numbering That Makes Sense to Your Accountant

Each document type — quotation, order confirmation, invoice, receipt — gets its own automatic numbering sequence, so a quotation number and an invoice number are never confused, and your accountant can follow a clean trail from proposal to payment without cross-referencing spreadsheets.

A Simple Example

You send a quotation for a website project: 40,000 THB plus VAT. The client accepts, so you convert it into an order confirmation to lock in the scope. Once the first milestone is delivered, you convert the same details into an invoice — 40,000 THB net, 2,800 THB VAT at 7%, 42,800 THB gross. The client pays, and since they're a Thai company, Lemon Invoice already flagged them for withholding tax — so the receipt shows the standard 3% withheld on the net amount (1,200 THB) alongside the payment received, matching what actually landed in your bank account.

Why the Flow Matters

Getting the sequence right isn't just about following convention. A clear quotation and invoice workflow means fewer questions from clients about what a document actually is, fewer mismatched numbers for your accountant to chase, and a paper trail that holds up whether you're reviewing it yourself or handing it to someone else at year end.

Keep Every Stage in One Place

Whether you're quoting a new client or issuing a receipt on a project you finished months ago, keeping quotations, order confirmations, invoices, and receipts in one connected flow means you're never rebuilding a document from memory — you're just moving the same one forward.