GST Reconciliation
Match your sales register against the GSTR/portal filing — flag mismatches, missing invoices and duplicates, and total the tax at risk.
01 · The opportunity
What it set out to solve
Every tax cycle, someone reconciles the sales register against what the portal actually shows — invoice by invoice. Miss a mismatch or a missing invoice and it's real money: lost input credit, or tax that should have been reported and wasn't.
02 · The approach
How I thought about it
I modelled the reconciliation the way an accountant does it: match on invoice number, compare the tax to the rupee, and classify every line — matched, amount-mismatch, missing, or duplicate — then quantify the exposure so the finance team knows exactly what to chase.
03 · What I built
- Two paste-in registers (your books vs the GSTR/portal filing)
- Invoice-level matching with tax compared to the rupee
- Status flags: Matched · Amount mismatch · Missing · Duplicate · In-filing-only
- A 'tax at risk ₹' total across every discrepancy
- One-click copy of the reconciliation summary
04 · The result
What changed
A working reconciliation tool that turns two registers into a ranked list of exactly what to fix — the kind of finance automation I build to run on a schedule for clients.
Reconcile the registers.
Paste your sales register and the portal filing (or use the samples) and watch it flag every mismatch, missing invoice and duplicate — and total the tax at risk. All client-side.
Your sales register
One invoice per line: invoice, party, taxable, tax.
GSTR / portal filing
The same columns, pulled from the portal. Mismatches and duplicates are expected — that's the point.
05 · Decisions & trade-offs
The questions I'd get asked about this, and my answers
Why compute this in the browser?
Tax data is sensitive, and for a public demo I'd rather nothing be uploaded. Matching invoices and comparing amounts is deterministic math I can stand behind — no black box, no server needed.
How does this reflect a real client build?
The same matching logic runs on live GSTR-2B / portal pulls against your accounting system, on a schedule — so discrepancies surface the day they appear, not at filing time. The demo is the engine; production is the pipes and the schedule.