According to a recent Supreme Court judgement dated 19/02/2008 in the case of Thiruvengada Pillai Vs. Navaneethammal and Anr., the stamp papers do not have any expiry period.
Input Tax Credit, GST refunds and Recovery of refunds- Roadblocks and way outs
GST LIVE Certification Course - 43rd Weekdays Batch(With Govt Certificate)