GST ITC reversal and interest for Rule 37 and Section 50.

Upload your ledger to identify invoices unpaid beyond 180 days, allocate payments, and generate an audit-ready 18% p.a. interest report.

Download sample workbook
$ itc-calc --mode exact_normal --cutoff 2025-03-31
Ready
1

Upload ledger

Upload a CSV, XLSX, or XLS ledger with Date, Debit (Rs), and Credit (Rs) columns.

Max file size: 15 MB
Drop CSV/XLS/XLSX here, or click to browse
Invoices → Credit (Rs)  ·  Payments → Debit (Rs)  ·  Tax Rate auto-detected
Use the sample ledger if you are preparing a file for the first time. Replace the demo rows with your ledger data and keep the same column names. Download sample XLSX Download sample CSV View sample output Invoices go in Credit (Rs). Payments go in Debit (Rs).
Rule 37 Flags ITC reversal where invoice payment is pending beyond 180 days.
Section 50 Applies interest calculation on delayed reversal/payment impact.
Assumption Results follow the payment sequence and supplier grouping in your uploaded ledger.
Rule 37 · 180-day window
Selected cutoff: 31/03/2025
Multi-sheet Excel file? to specify the sheet name.
Advanced options
Use only when the workbook has multiple sheets.
Rows to ignore before the header row.
2

Choose report format

Upload a file first — the estimate panel will check row count, supplier count, and runtime for the format you select.

Not sure? Start with Styled audit XLSX. Supplier sheets for line-by-line reconciliation. CSV ZIP for Tally or downstream import.
3

Review estimate and generate report

Review the estimate below, then click Generate. The file downloads automatically when the calculation completes.

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Rows
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Recommended format Styled audit XLSX is the audit-ready default.
Detected input preview
First rows after date parsing and supplier/date sorting