May 2026 WPI Revised to 9.88%: How Finance Teams Should Handle Provisional-to-Final Data
By Ravi Sisodia · Reviewed by CA Divyanshu Sengar · Updated 5 October 2026
2-minute summary
- The final May 2026 WPI index was revised to 110.1 from the provisional 109.9, and May inflation to 9.88% from 9.68%.
- The May revision shows why finance systems need versioned macro data rather than silent overwrites of provisional releases.
- Later WPI publications should be linked back to the original estimate so users can see what changed, when it changed and which models depended on it.
Current position
May 2026 demonstrates the provisional-to-final mechanism: the index and inflation rate were revised when more response data became available. A controlled dashboard should preserve both snapshots and tag the final value rather than deleting the earlier number.
Control and evidence map
| # | Control / evidence requirement | |
|---|---|---|
| 1 | Dashboards should version economic data: keep the original provisional print, final revision, source date and downstream forecasts affected by the change. | |
| 2 | Store provisional and final values in separate dated fields. | |
| 3 | Identify contracts, forecasts and board packs that used the earlier estimate. | |
| 4 | Recalculate only where policy or contract requires the final index. | |
| 5 | Explain revision impact separately from economic movement in a new month. | |
Worked example
A covenant or escalation model built on May provisional data should flag the revision and recalculate only if the contract or internal policy uses final WPI.
Common mistakes
- Do not overwrite provisional data without an audit trail.
- Check whether a contract specifies provisional or final index.
- Avoid presenting a revision as a new current-month inflation shock.
Frequently asked questions
Was May inflation originally 9.88%?
No; the provisional rate was 9.68% and the final rate became 9.88%.
Should the provisional number be deleted?
No; keep it for auditability.
Does a revision mean May prices changed retroactively?
It means the statistical estimate was finalised with additional information.
Which number should a contract use?
Follow the contract wording on provisional or final index treatment.
Official sources
- Press Information Bureau / Department for Promotion of Industry and Internal Trade - Provisional WPI, Output PPI and Experimental Input PPI for July 2026; final May 2026 indices (PIB PRID 2299432; 2026-08-14)
- Press Information Bureau / Department for Promotion of Industry and Internal Trade - Provisional Wholesale Price Index for August 2026 (PIB PRID 2309977; 2026-09-14)
Disclaimer
Educational and professional reference only; confirm the current law, rates and the facts of your case before relying on this page.