Question 1

What is BillKlong (บิลคล่อง)?

Accepted Answer

BillKlong (บิลคล่อง) is a free online tool at billklong.com for creating quotations, invoices/billing notes, receipts and Thai tax invoices. The name combines "bill" with the Thai word "klong" (คล่อง), meaning fluent or effortless, so it reads as "easy billing". It is built for freelancers, shops and SMEs in Thailand and works instantly without sign-up.

Question 2

Is BillKlong really 100% free? Are there any hidden fees or watermarks?

Accepted Answer

Yes, BillKlong is completely free without any conditions, limits, or hidden fees. We never place any watermarks on exported PDF documents.

Question 3

Is my business data secure? Is financial data stored on your servers?

Accepted Answer

Completely secure. BillKlong operates strictly client-side. Your customer information, tax ID numbers, and financial data are never transmitted to or stored on any external server. Drafts reside only in your local browser storage.

Question 4

Is the tax invoice generated compliant with Thailand Revenue Code Section 86/4?

Accepted Answer

Yes. When selecting the "Tax Invoice" (TAX) document type, all 8 statutory requirements under Section 86/4 (including the 13-digit Tax ID, Head Office/Branch designation, and explicit VAT separation) are provided.

Question 5

What are the applicable Withholding Tax rates and how are they calculated?

Accepted Answer

Under Revenue Department Order Tor.Por. 4/2528, standard rates are 3% for services and freelance contracting, 5% for rental, 2% for advertising, and 1% for transport. The calculation applies to the pre-VAT subtotal, which BillKlong handles automatically.

Question 6

How do I print or export the completed document as an A4 PDF?

Accepted Answer

Click the "Print / Save PDF" button on the navbar or mobile action bar. In the browser print dialog, choose "Save as PDF" as the destination. BillKlong's calibrated print CSS ensures an exact, single-sheet A4 output.

Document Header

Line Items & Services3 items

Revenue Code Sec 86/4 (Full Tax Invoice)

Order Tor.Por. 4/2528 (Withholding Tax)

Revenue Code Sec 105 (Receipt Issuance)

PromptPay EMVCo Standard (Bank of Thailand)

Document Type	Objective	Lifecycle Stage	Tax Status
Quotation (QT)	Propose pricing, scope of work, and terms	Pre-sale / Proposal	Informational only
Invoice / Bill (INV)	Request payment with defined credit terms	Post-delivery / Billing Cycle	Accounting liability proof
Receipt (REC)	Acknowledge received funds	Upon receipt of payment	Compliant under Sec 105
Tax Invoice (TAX)	VAT input/output credit documentation	When the tax point triggers	Legal tax credit under Sec 86/4