Invoicing, payments & tax — sorted in one app
The simplest way to invoice clients, get paid the exact amount by PromptPay QR, and produce correct Thai tax documents.
Paid to your bank • zero fees • first bill in a minute
Works with the tools Thai businesses use every day
Everything you need in one place
Small tools that do the heavy lifting — from sending a bill to filing your taxes.
Exact-amount PromptPay
Customers scan and pay the exact amount, straight to your bank — zero fees, fewer fake slips.
Revenue-Dept compliant
Tax invoices, receipts and 50 Bis in the official format — VAT and withholding done for you.
Bilingual in one click
Switch Thai/English on every page and document — great for foreign clients.
Up and running in 3 steps
Create a bill
Pick a client and add items. VAT and withholding are calculated automatically.
Send via LINE
Your client opens a pay page and scans a PromptPay QR with the amount pre-filled.
Get paid + documents
Money lands in your bank. Issue the receipt and 50 Bis certificate instantly.
Simple, honest pricing
Start free, upgrade as you grow, cancel anytime.
Starter
- 5 bills / month
- PromptPay exact-amount QR
- Receipts & tax invoices
- LINE payment links
Freelancer
- Everything in Starter
- 20 bills / month
- WHT 50 Bis certificates
- Quotations + unlimited customers
Pro
- Everything in Freelancer
- Unlimited bills
- Remove BillsOS branding — your own logo
- CSV export + multiple businesses