Why OKOSUM
A different approach to compliance tools.
Instant Results
No waiting, no processing queues — every tool runs in your browser and gives you an answer immediately.
No Signup Needed
Use every tool free, with no account, no email wall, and no credit card — ever.
Built for Accuracy
Our tools follow the same official formats and formulas the GST portal itself uses — not guesswork.
Made for India
Designed specifically around Indian GST compliance — not a generic tool retrofitted for it.
Available Tools
Live now, free to use.
GSTIN Predictor
Predict the exact 15-character GSTIN a PAN will receive on GST registration — before it's even filed. Enter your state, PAN, and registration count to get the full format instantly, using the same checksum logic the GST portal itself uses.
Open tool →Coming Soon
What we're building next.
HSN Code & Tax Rate Finder
Look up the correct HSN/SAC code for any product or service, along with its current applicable GST rate and conditions — all in one search.
GST Reconciliation Tool
Match your purchase register against GSTR-2A/2B automatically, flag mismatches, and see exactly what needs correcting before filing.
Bulk GSTIN Predictor
Upload a spreadsheet of PANs and get predicted GSTINs back in bulk — built for accountants and CAs managing multiple clients.
See the full roadmap on our Upcoming Tools page, or suggest a tool you'd like us to build.
Ready to simplify your GST workflow?
Start with the GSTIN Predictor — free, instant, no signup.
Try it now →