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Accounting Software | Tally Migration

Tally Prime to cloud accounting in 2 to 3 weeks. CA-supported, validated.

Move your COA, opening balances, vendors, customers, items, GST history and TDS deductee history without losing a trail. Validation runs before cutover. Dual-run for one month. Rollback documented and CA-validated. Most teams cut over inside one quarter.

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Tally Migration

How most Tally migrations are attempted

Migration: the project that always slips a quarter.

The intent is clear. The reality is messier:

  • An IT consultant downloads the Tally backup, opens it in their copy of Tally, exports each ledger to Excel, and then discovers the COA isn't standardised across companies.
  • Opening balances reconcile to within ₹1.34 because someone ran a JE that wasn't reversed. Tracing it takes a week.
  • Vendor and customer masters carry duplicates from years of typos. The migration multiplies them. The CA flags them at FY-end.
  • GST and TDS history don't migrate at all. 'We'll re-key the last six months' is the plan that quietly slips.

By the time the cutover happens, six weeks have turned into six months, and the team has lost faith in the migration before they've started using the new system.

How it works

Five steps. The migration runs against a backup, not your live books.

Your live Tally is never written to. Validation, cleanup and dual-run all happen against a sandbox copy. Cutover only happens once the variance reports are clean and your CA has signed off.

Step 01

Tally backup imported, read-only

Your Tally Prime backup uploads to a sandbox. The import reads every company, every ledger, every voucher type, without writing back to your live Tally.

Step 02

Validation report before cutover

Opening balance variances, COA mismatches across companies, duplicate masters, FY misalignment and GST history gaps are surfaced as a report your CA and AP team review before any cutover decision.

Step 03

Master data cleaned in place

Duplicate vendors and customers are merged in the sandbox. The COA is reconciled to a master across companies. Opening balances align. The cleanup happens before the data hits your live system.

Step 04

Dual-run, one month

Both Tally and OneFinOps run in parallel for one month. Every transaction posts to both. The reconciliation report shows variances at the line level, every day.

Step 05

Cutover with rollback documented

When the dual-run is clean, OneFinOps becomes the system of record. Tally is preserved as read-only for 12 months. A rollback plan is documented and CA-validated for the first 30 days.

What the migration tooling does

Capability, input, output.

  • Tally backup parser

    Input
    .tcp / .900 backup file from Tally Prime or Tally Server 9
    Output
    Sandbox load with per-company ledger and voucher tree

  • COA migration

    Input
    Tally COA across all companies in the backup
    Output
    Master COA mapped to Schedule III and Ind-AS

  • Opening balance validator

    Input
    Tally trial balance plus open journal entries
    Output
    Variance report with per-ledger drill-down

  • Master deduplication

    Input
    Vendor, customer and item masters from every company
    Output
    Merged set with retention of legacy IDs and a merge audit trail

  • GST history migration

    Input
    Filed GSTR-1, 3B and 9 from Tally
    Output
    Imported into the GST register, period-locked

  • TDS deductee migration

    Input
    Tally TDS register across FYs
    Output
    Vendor PAN, section and deduction history per FY

  • Dual-run reconciliation

    Input
    Tally postings plus OneFinOps postings, daily
    Output
    Daily variance report at the line level

  • Cutover and rollback

    Input
    OneFinOps state plus Tally state at cutover
    Output
    CA-signed cutover plan plus 30-day rollback runbook

Compliance + integrations

A migration that respects the books your CA already signed off on.

Nothing is overwritten in your live Tally. Nothing posts to OneFinOps without validation. The migration itself is captured as a tracked event with the same audit-trail rigour that applies to ongoing accounting.

Regulations we work within

  • Section 128, Companies Act 2013

    Books of account preserved for 8 years. Tally retained read-only for 12 months post-cutover.

  • Rule 11(g), Companies Act 2013

    Audit trail with edit log captured from day one. The migration cutover itself is a tracked event.

  • Section 35, CGST Act + Rule 56

    GST records retained for 6 years. Legacy GST history imported and locked.

  • Section 44AB, Income Tax Act

    Tax-audit FY books reconciled before cutover. CA sign-off required for the cutover decision.

  • ICAI SA 600

    External-audit validation pattern followed. Audit-pack generated for the migration period.

Connects to

  • Tally Prime Read-only import from .tcp / .900 backup
  • Tally Server 9 Multi-user, multi-company server backups
  • Zoho Books Native migration from backup
  • QuickBooks India IIF and Excel migration
  • Marg / Busy Database export migration

Tally Migration FAQ

What buyers ask.

How long does migration actually take? We've heard 2 weeks and we've also heard 6 months.

For a single-entity Tally Prime user with up to 24 months of history and a clean COA, 2 to 3 weeks is realistic, including the dual-run. Multi-company Tally setups, or businesses with FY misalignment, messy COA or heavy customisation, run 4 to 8 weeks. The validation report at the end of week 1 tells you which path you're on. We don't quote a date until the report is in.

Do we need to stop using Tally during the migration?

No. Tally stays live. The migration runs against a backup. The dual-run posts to both systems in parallel. You only stop using Tally on the cutover date, and even then, it's preserved read-only for 12 months as the historical reference.

Our books are mid-FY. Can we migrate now or do we have to wait until April?

You can migrate mid-FY. The opening balance is taken from the last closed month's trial balance. The FY's history before that month migrates as historical data. The current FY's GSTR and TDS filings continue uninterrupted. Most teams that migrate mid-FY do so in October to December, which gives a clean Q4 in the new system.

What about our custom Tally TDLs and report formats?

Custom Tally TDLs (the TDL programming language for custom reports and vouchers) don't migrate directly. The custom reports get rebuilt as MIS dashboards in OneFinOps. The custom voucher types map to OneFinOps's transaction types, with field mapping documented. Most teams find their TDL reports were workarounds for things OneFinOps does natively.

Our CA signed off on last FY in Tally. Does the audit trail follow?

Yes. The CA sign-off, the audit notes and the DSC-signed Form 3CD are imported as evidence on the migrated period. Last FY remains locked in OneFinOps with the same evidence the CA finalised in Tally. The CA reviewer access carries forward.

Cost of migration. Is this billed?

A single-entity Tally Prime migration up to 24 months of history is included in the standard subscription. Multi-company Tally, custom TDL rebuilds, or migrations from forked Tally distributions (Tally.ERP 9, Tally Solutions custom builds) are scoped separately. The validation report quotes effort before any commitment.

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Related features

Upload your Tally backup. See the validation report by morning.

Sandbox-only import, free. Your live Tally isn't touched. The validation report tells you whether you're a 2-week migration or a 6-week one, and on what conditions.

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