fortax-gstr1-and-3blisted

# GSTR-1 and GSTR-3B Needs Python 3 and internet: runs `scripts/fortax.py` (the Fortax engine on ai.fortax.in; your file is processed and not stored). Two outputs for one period: the GSTR-1 JSON the CA uploads on the portal, and the GSTR-3B working paper the CA files from. The engine builds GSTR-1 and computes the figures. You read its summary out, judge what code cannot (HSN/SAC for an item), check the register for the traps below, and assemble 3B. The CA uploads, files, pays and signs. ## Inputs (look in `<Client>/<FY>/GST/<YYYY-MM>/` or wherever the CA dropped files) - **Sales register** for the period — any accounting software export (Tally, Busy, Zoho Books, Marg, an ERP, a hand-kept Excel), .xlsx or .csv, one row per invoice or per invoice line. Needs invoice no, date, buyer GSTIN, buyer name, place of supply, taxable value, rate, IGST/CGST/SGST, cess, HSN/SAC, B2B/B2C, credit/debit notes, exports, SEZ, nil/exempt. - **Purchase register** with supplier GSTIN, invoice no and date, ITC amount, eligible/ineligible tag. - **GSTR-2B** for the period (portal JSON, zip or Excel) — see `fortax-gstr2b-reconciliation`. - **Previous period's 3B** — carry-forward ITC, negative liability, RCM paid. - **RCM register** — GTA, legal fees, import of services, security services, others notified. If a file is missing, list it under "Data needed" and continue with what exists. ## Step 1 — lock the period - Month or quarter, and filer type (monthly or QRMP). Ask the CA if it is