You have the agreement. Both parties signed it. The other side is now denying every word of it, and the court will not look at your copy — because nobody paid a few thousand rupees of stamp duty when it was executed.
Stamp duty is a tax on the document recording a transaction rather than on the transaction itself, and under Section 35 an instrument that is not duly stamped generally cannot be admitted in evidence until the duty and a penalty are paid.
The bottom line
What it taxes: instruments — sale deeds, leases, gift deeds, mortgages, share transfers, agreements — listed in Schedule I of the Indian Stamp Act, 1899.
Why rates differ everywhere: stamp duty is collected and appropriated by the states, and each state sets its own rates.
What happens if you skip it: the document is inadmissible under Section 35 until the duty and penalty are paid, and it can be impounded by whoever it is produced before.
What stamp duty is
Stamp duty is a government tax on documents, which the Act calls instruments, recording certain transactions: sale deeds, leases, gift deeds, mortgages, share transfers, agreements and more.
It is paid by affixing or denoting a stamp on the instrument, which then serves as proof the tax was paid. The primary purpose is revenue. The side effect, which matters more to the person holding the document, is that a stamped instrument carries greater legal weight and is admissible where an unstamped one is not.
Why it matters beyond the money
Stamp duty sits at the intersection of revenue and enforceability. A properly stamped instrument is admissible as evidence. An unstamped or under-stamped one generally is not, until the deficiency is cured with a penalty on top.
Which turns a small saving at signing into a large problem later. Pay the duty correctly and the document protects you. Skip it and your strongest piece of paper stops working at exactly the moment a dispute makes you need it.
Instrument, and chargeability
Two provisions carry the structure.
Section 2 defines an instrument as every document by which any right or liability is created, transferred, limited, extended, extinguished or recorded. The duty attaches to the document, not to the underlying deal as such.
Section 3 makes instruments listed in Schedule I chargeable with stamp duty at the specified rates. So the question in every case is the same one: is this document a listed instrument, and what is the prescribed duty on it?
Why the rate depends on where you are
Stamp duty is largely a state matter. Under the Constitution the duty is collected and appropriated by the states within which it is leviable, and each state sets its own rates. Many have their own stamp laws or amendments on top.
That is why the duty on the same sale deed differs between Maharashtra, Karnataka and Delhi. The Centre fixes rates for a limited set of instruments — bills of exchange, cheques, promissory notes, certain financial securities — but most everyday stamp duty is decided by your state, and the state's current rate is the only one worth relying on.
Which documents attract it
The common ones: sale and conveyance deeds for immovable property, gift deeds, lease and leave-and-licence agreements, mortgage deeds, partition deeds, powers of attorney, share and securities transfers, debentures, insurance policies, promissory notes, and a long tail of ordinary agreements.
Securities and financial-market transactions are now handled differently. Following amendments to the Act, duty on them is levied in a more uniform, centralised way, collected through stock exchanges, depositories and clearing corporations.
How it is paid
- Physical stamp paper — the traditional non-judicial stamp paper.
- Franking — a stamp impressed by an authorised bank or agent.
- E-stamping — a tamper-evident electronic stamp certificate, now the standard in many states, usually issued through an authorised central record-keeping agency.
The duty is generally paid before or at the time the instrument is executed. Only then is the document ready for use, and for registration where that is required.
What happens if you do not pay
- Inadmissibility under Section 35. An instrument not duly stamped cannot be admitted in evidence for any purpose, or acted upon, until the duty and a penalty are paid.
- Impounding. An authority before whom an under-stamped instrument is produced can impound it.
- Penalty. The deficient duty plus a penalty, which can run to a multiple of the deficiency, has to be paid to make the document usable.
An unstamped agreement is not void as a contract. It is simply unusable as evidence, which in a litigation is close to the same thing.
Undervaluation and adjudication
Stamp duty on property is usually calculated on market value, or on the higher of the declared consideration and the state's circle or ready-reckoner rate. Under-declaring the value to save duty is common and is a bad bet.
The registering officer can refer a suspected undervalued instrument to the Collector, who determines the correct value and the deficient duty after a hearing. Parties who want certainty can go the other way and seek adjudication of the proper duty from the Collector in advance, before any dispute exists.
The proposed Indian Stamp Bill, 2023
The 1899 Act is a pre-Constitution law and much of it now reads that way. A draft Indian Stamp Bill, 2023 was released for public consultation to modernise the regime.
The proposals include express provisions for e-stamping and digital records, recognition of electronic signatures, simplified language, and higher penalties — the maximum penalty for contravention rising from ₹5,000 to ₹25,000, for instance.
As of 2026 it remains a draft. The Indian Stamp Act, 1899, read with each state's amendments, is still the operative law.
A worked example
A buyer purchases a flat. The sale deed is an instrument chargeable to stamp duty at the state's rates, calculated on the higher of the agreement value and the circle rate. The buyer pays through e-stamping before executing and registering the deed.
Now change one thing. The parties under-declare the value to save duty. The registering officer refers it to the Collector, who can demand the deficient duty plus a penalty, and until that is paid the under-stamped deed is not admissible if a dispute arises.
The saving was notional from the start. Paying the correct duty up front costs less than curing a deficiency later, and it costs far less than losing an argument you would otherwise have won.
Common mistakes
- Under-stamping to save money, which risks inadmissibility and penalties later.
- Assuming one rate applies nationwide. It varies by state.
- Declaring a property value below the circle or ready-reckoner rate.
- Leaving ordinary agreements unstamped, then finding they cannot be used as evidence.
- Treating stamp duty and the registration fee as one charge. They are separate.
Frequently asked questions
What is stamp duty? A government tax on documents, or instruments, that record transactions. It is paid by affixing or denoting a stamp, primarily to raise revenue, and it gives the document legal validity.
Why does stamp duty differ from state to state? Because it is collected and appropriated by the states, and each state fixes its own rates within the constitutional framework.
What happens if a document is not stamped? Under Section 35 it generally cannot be admitted in evidence or acted upon until the duty and a penalty are paid.
How can I pay stamp duty? Through physical stamp paper, franking or e-stamping, depending on your state, usually before or at the time of executing the document.
Is the Indian Stamp Act being replaced? A draft Indian Stamp Bill, 2023 has been proposed to modernise the law, but as of 2026 the Indian Stamp Act, 1899, with state amendments, remains in force.
Can I stamp a document after signing it? The deficiency can usually be cured by paying the duty and a penalty, but the document does not work as evidence until that is done. It is a repair, not a plan.