Open-source helpers for Indian shops, traders and developers building billing software: GST maths, GSTIN checks, HSN codes, amount in words and UPI QR codes.
| Repo | What it does | Use it online |
|---|---|---|
| gst-calculator-india | Add or remove GST with CGST/SGST or IGST split (JS + Python) | billingbazaar.in/tools/gst-calculator/ |
| gstin-validator | Validate a GSTIN offline: state, PAN, check digit (JS + Python) | billingbazaar.in/tools/gstin-validator/ |
| hsn-sac-codes-india | 446 HSN + 203 SAC codes with Hindi/Hinglish search words (JSON/CSV) | billingbazaar.in/tools/hsn-code-finder/ |
| gst-state-codes-india | GST state codes of all states and UTs (JSON/CSV) | billingbazaar.in/tools/gst-state-codes/ |
| amount-in-words-indian | Rupees in words with lakh/crore for invoices and cheques (JS + Python) | billingbazaar.in/tools/amount-in-words-converter/ |
| upi-qr-code-generator | UPI payment QR links for any UPI app (JS) | billingbazaar.in/tools/upi-qr-code-generator/ |
More free tools (GST invoice generator, quotation maker, barcode generator, logo maker …): billingbazaar.in/tools
| Repo | What it does | Use it online |
|---|---|---|
| house-help-salary-calculator | Maid / house-help salary with leave deduction, bonus and cost per hour | open |
| upi-id-validator | Check a UPI ID and see which app and bank its handle belongs to | open |
| savings-fd-interest-calculator | Daily vs quarterly interest and FD maturity | open |
These repos are building blocks. If you just want GST billing, stock and udhaar sorted for your shop, a billing app does
all of this on every bill – we use and set up Vyapar (step-by-step Vyapar guides).
New to Vyapar? Sign up with referral code NXW3QY, or get a free demo and installation.