How e-stamp duty is calculated by state

Key takeaways

• Duty is decided by a chain: instrument and article, then state, then the amount it is measured on, then the duty shape, then caps, minimums and surcharges.
• India's stamp law is layered. A central Act supplies the framework, and states set most rates through their own schedules. A few instrument types, such as cheques, promissory notes and share transfers, have rates fixed centrally.
• There are three shapes: flat (the same sum regardless of value), ad valorem (a percentage of an amount), and slab (a rate that steps up as the amount or term crosses thresholds). Many articles mix them, for example a percentage with a floor and a ceiling.
• The same document costs different amounts in different states because the article, the measure, the rate and the cap can each differ, and some states add cess or surcharges.
• For property documents the measure is often the higher of the stated consideration and a government valuation. For leases it is usually driven by rent, term and deposit or premium.
• Under-stamping is expensive to fix later: the document may be refused as evidence until the shortfall and a penalty are paid. Registration is a separate step with its own fee.
• StampMitra's API does not derive duty from your consideration. You supply stampDutyAmount; the API checks that it is a valid purchase for the state and article and prices everything around it.

Why does stamp duty differ from state to state?

India's stamp law has a central skeleton and state muscle. The Indian Stamp Act, 1899 is the original central statute, and the Constitution splits the power to set duty between the Union and the states. The rates of duty on a short list of instruments (bills of exchange, cheques, promissory notes, bills of lading, letters of credit, insurance policies, share transfers, debentures, proxies and receipts) are fixed by Parliament. For every other kind of document, rates are set by each state, which has its own amended Act or its own schedule of articles and has revised them over the decades.

The consequence is that there is no national table. Two states can have the same underlying document and give it a different article number, a different name, a different measure and a different rate. Some states have consolidated their law into a modern Act. Some still operate on the original statute with local amendments. Some charge extra levies on property documents, often described as cess or surcharge, for local bodies or infrastructure. When people say "stamp duty is a state subject", this is what they mean in practice: each state keeps its own books, and your software has to ask the state's books, not a national rule of thumb.

This is also why you should be suspicious of any blog post with a rate in it, including a rate quoted from a reputable news article two years ago. Governments revise duty to stimulate property markets, to raise revenue or to harmonise slabs, and the revision might be a temporary concession that lapses on a date. The only trustworthy sources are the state's own notifications and its authorised stamping system.

What are the inputs to a stamp duty calculation?

Strip away the vocabulary and every calculation uses the same five inputs. You can use them as a checklist when a user tells you "I just need stamp paper for my agreement".

1. The instrument and its article. What the document is in law, not what the parties call it.
2. The state. More precisely, the state whose law governs stamping of this instrument, which is generally where it is executed or where the property sits, depending on the type of document.
3. The measure. The amount the duty is computed on: the consideration, the market value, the rent over the term, the loan amount, or no amount at all for a flat-duty article.
4. Attributes that change the rate. The term of a lease, whether the buyer is a particular class of person, whether the property is urban or rural, area and location, and whether the document is a first-time or a subsequent one.
5. The date. Rates and concessions apply from notified dates, so a document is stamped at the rates in force on the relevant date.

A calculation that ignores any of these is a guess. Worse, it is a guess that looks like arithmetic, which is how a confident wrong number reaches a customer.

How do instrument type and article decide the duty?

The word "article" comes from the schedule attached to a state's stamp law, which lists kinds of instruments in numbered entries. Each entry says what the instrument is and how duty on it is computed. An agreement, a sale deed, a lease, a mortgage, a power of attorney, an affidavit, an indemnity bond and a partnership deed each sit under different entries, and each entry has its own rule.

Two points trip people up. First, the entry is chosen by the substance of the document. A "rental agreement" that is in law a lease of immovable property for a term is stamped as a lease, even if the parties call it a licence agreement or an agreement to let. Whether a particular arrangement is a lease or a mere licence is a legal question, and it is exactly the kind of question where you should not let a product manager's intuition decide. Second, article numbers are not portable. The article that covers a certain kind of agreement in one state's schedule can have a different number, or a different scope, in another's. This is why the StampMitra catalogue is scoped by state: you read the list of articles for the state, you do not carry an article code across states.

A document that contains several things can attract several duties or be charged on the dominant character, depending on the state's rules. A loan agreement that also creates a security interest, a lease combined with a sale, or an agreement that includes an indemnity are all examples where classification needs a person with legal training. Your product should offer structured options and a way to ask a human, rather than inferring the article from a free-text description. StampMitra's service terms put this plainly: the developer selects the right category and article, and must not knowingly choose a wrong classification to reduce statutory charges.

What are flat, ad valorem and slab duties?

Every article uses one of three shapes, or a combination.

Flat duty is the easy case, and the article alone decides it. If your product only handles flat-duty articles, your duty logic can be a lookup per state.

Ad valorem duty is a percentage multiplied by an amount, and the hard part is the amount. For a sale of property it is typically the consideration or the market value, whichever the state's law makes relevant. For a loan or security document it is generally the amount secured. For an agreement it might be the value the agreement concerns.

Slab duty is where most mistakes happen, because there are two different ideas hiding under one name. In a whole-amount slab, once the amount crosses a threshold, the new rate applies to the entire amount. In a marginal slab, like income tax, each rate applies only to the part of the amount inside its band. States use both. An amount a rupee over a threshold can therefore cost almost the same as one just under it (marginal) or noticeably more (whole-amount). If you write your own calculator, you must know which one the article uses, which is one more reason not to.

Many articles also carry a minimum (a floor below which duty is not charged less), a cap (a ceiling regardless of value) or both. A percentage with a floor and a ceiling behaves like a flat duty at the extremes and like ad valorem in the middle. Mortgages and some lease classes are well-known places to find caps, though which states cap what is for the state's schedule to say.

Consideration or market value: what is the duty measured on?

For documents that transfer or create rights in property, the measure is often not what the parties wrote down. Many states compare the stated consideration with a government valuation of the property, commonly called a circle rate, ready reckoner rate or guidance value, and charge duty on the higher of the two. The reason is simple: if duty were charged only on the stated price, parties would have an incentive to understate it. The government valuation is published per locality, per type of property and sometimes per floor or age of construction, and it is revised periodically.

For leases the measure is built differently. It is usually a function of the rent, the term and any deposit or premium. A common structure is that the duty depends on the total rent over the term, plus a share of any non-refundable premium, and in some states the refundable deposit is also counted. The term matters on its own as well, because leases beyond certain lengths fall into different slabs and are treated differently for registration. Whether a deposit is counted, and how, is a state-by-state detail you need to read from the article.

For loans, guarantees and security documents, the measure is typically the principal amount secured, sometimes limited by a cap. For powers of attorney and agreements, the measure can be a flat sum, the value of the property dealt with, or the consideration. The point to take away is that "value" is not one concept. Your user interface should ask a question that matches the article, for example "total rent for the term" or "agreed sale price", and not a generic "value of agreement".

What are cess, surcharges and other add-ons?

Duty on property documents in some states is topped up by a separate levy, such as a surcharge for local bodies or a cess for metro or infrastructure funds, charged as a percentage of the duty or of the value. A document can also carry a separate registration fee, which is not stamp duty. The StampMitra API reflects the first kind of thing directly: the state detail response has a cessRequired flag, and a stamp line on an order can carry a cessAmount where the article requires one. The API also has a propertyAreaRequired flag for states that want the area of the property on the stamp, and sroRequired where the sub-registrar office is part of the application.

Treat registration fees and stamp duty as separate costs in your model. The first is paid at registration to the registration authority, the second is paid when you buy the stamp. Product pages that show "total cost of agreement" without distinguishing them confuse users when the second bill arrives.

Why does the same document cost different amounts in different states?

Because each link in the chain can differ independently. Here is a deliberately artificial comparison for one document, a three-year lease of a flat at a monthly rent of 20,000 rupees with a refundable deposit of 60,000 rupees, in three fictional states. The rates and rules are invented to show the mechanics. They are not any real state's rules.

Look at what actually produced the spread. State A and State C both ignore the deposit, but State A uses a percentage and State C a flat sum. State B counts the deposit, uses a higher percentage, caps the result and adds a cess. None of these differences is exotic, and every real state has its own mix. The lesson for your software is that "what rate does the state charge" is the wrong question. The right question is "what does this state's article say about this instrument, and what measure does it use". That is why a catalogue of articles per state, rather than a rate table, is the right data structure.

How do worked examples look for each duty shape?

All figures below are illustrative. The states are fictional and the rates are invented.

Example 1, flat duty. An affidavit in State A attracts a flat duty by article, regardless of what it says. Duty equals the article's sum. Nothing about the content, value or parties changes it. The only way to get this wrong is to choose the wrong article.

Example 2, ad valorem with a floor. A sale deed in State B is charged at 5 percent of the higher of consideration and valuation, with a minimum duty of 500. The parties declare a price of 40 lakh. The government valuation of the property is 46 lakh. The measure is the higher figure, 46 lakh, so duty is 5 percent of 46 lakh, which is 2.3 lakh. If the declared price had been 3,000 rupees against a valuation of 5,000 rupees, five percent of 5,000 would be 250, so the floor of 500 would apply instead. The floor is what protects tiny transactions from producing absurdly small duty.

Example 3, a marginal slab. A bond in State C has duty of 0.1 percent on the first 10 lakh of its amount, 0.2 percent on the next 10 lakh, and 0.3 percent above 20 lakh. For an amount of 25 lakh, duty is 0.1 percent of 10 lakh (1,000), plus 0.2 percent of 10 lakh (2,000), plus 0.3 percent of 5 lakh (1,500), a total of 4,500. Under a whole-amount version of the same table, all 25 lakh would be charged at 0.3 percent, which gives 7,500. Same table, different reading, different bill. Always check which reading the article uses.

Example 4, a cap. A loan agreement in State A is charged at 0.2 percent of the amount secured, capped at 20,000. For a loan of 1 crore, 0.2 percent is 20,000, so the cap and the computed figure coincide. For a loan of 5 crore, 0.2 percent is 1 lakh, but the cap holds duty at 20,000. A product that handles small loans correctly can quietly overcharge large loans if it ignores the cap.

Example 5, rounding to what can be issued. A computed duty of 1,100 is not necessarily purchasable. E-stamps are issued in denominations that the state or the issuing system allows. Some states permit any amount within a range, some allow only a list of fixed denominations, and some permit a total built from a limited number of papers. A duty of 1,100 in a fixed-denomination state might need to be bought as 1,000 plus 100 on two papers, or rounded up to the next available denomination, depending on what the state allows. The StampMitra API surfaces this: the article catalogue carries an optional allowedAmounts list, the state carries minAmount and maxAmount, and the calculation response carries papers and paperCount.

Which exemptions and concessions exist, in general terms?

Stamp laws contain exemptions and concessions, and they are as varied as the rates. Typical categories include instruments executed by or in favour of the government, certain charitable or educational purposes, specific classes of documents that are exempt under a state's schedule, and concessions for particular buyers, such as women purchasers, senior citizens or first-time buyers, in states that offer them. Some are permanent, some are time-limited, and some require a certificate or a notification to be quoted.

Because of this variety, a calculator that only knows rates will overcharge in some cases and undercharge in others. Do not build exemption logic into your product from memory. Two safer patterns exist. One is to ask the user whether they believe an exemption applies, record that, and route the order to a person who can check it. The other is to use a state's own calculator output as the input to your order. Either way, the decision that an exemption applies belongs to someone qualified to make it. The StampMitra service terms say as much: where duty is determined by an authority or source, rely on that determination rather than presenting your own figure as authoritative.

What happens if a document is under-stamped?

In broad terms, an instrument that is not duly stamped has a legal problem in the places where it matters most. It may not be accepted as evidence in court or by a public authority until the deficiency is made good, and making it good usually means paying the shortfall plus a penalty that can be a multiple of the shortfall, with the exact rule depending on the state. A document can also be impounded by an authority that notices the deficiency. Courts have in recent years leaned towards treating insufficient stamping as a curable defect rather than one that destroys the document, but "curable" still means a bill and a delay.

States provide a route to settle the question in advance, often called adjudication: you present the document to the Collector or equivalent officer, who gives an opinion on the duty chargeable. It takes time and is worth the cost for unusual or high-value documents where classification is uncertain. A deficit can also be paid later as deficit duty, and some states run campaigns or amnesties that lower penalties for a window.

For a product team, the point is not to learn the penalty provisions. It is to design so that under-stamping is hard. Make duty decisions explicit, keep an audit trail of who chose the article and the amount, show the user the basis, and never let a front end quietly pick the cheapest option.

Does registration change the stamp duty?

Registration and stamping are different obligations. Stamp duty is a tax on the instrument. Registration is a public record, governed by the registration law, with its own fee. Some documents must be registered to be effective, with property sales and longer leases being the classic examples, while others do not need registration but still need stamping. The rules depend on the document, its term and its value, and in some states, on additional local requirements. Even where registration is optional, many parties register to strengthen proof.

The practical sequence is that the document is stamped first and registered afterwards. An unregistered but properly stamped document might be usable for some purposes and not others. A registered but under-stamped document has a defect that surfaces when it is relied upon. For a rental platform, this means your journey should treat three states separately: stamped, executed and registered, and should not tell users that buying an e-stamp finishes the process. StampMitra's API handles the first. Execution, e-sign and registration happen elsewhere.

When must the e-stamp be bought and how long is it valid?

An e-stamp certificate is dated and carries a unique number. Two timing questions come up in practice. First, the stamp should be purchased on or before the date of execution of the document. A stamp bought after the document is signed invites questions in most places. Second, some states place a window on how long a purchased e-stamp remains usable, after which it must be used, or refunded or replaced where the state allows. Refund of an unused stamp is generally possible within a limited period, subject to conditions and a deduction in some states.

Do not hard-code any window. Read it from the state's rules or the issuing system, and design your workflow so that the stamp is bought close to execution rather than weeks ahead. In StampMitra's API, the stamp lifecycle has PLACED, ASSIGNED, GENERATING, VERIFYING and VERIFIED states, plus POST /v1/estamp/stamps/:stampId/cancel and .../replace routes with their own constraints, so a stamp that was ordered too early is something you handle through those, not through your own database.

How does the StampMitra API fit into this method?

Now put the API in its place in the chain. Steps one to three of the method, deciding the instrument and article, the state and the measure, are yours. The platform helps with the catalogue part: GET /v1/estamp/states lists states, GET /v1/estamp/states/:stateCode reports flags like eStampAvailable, sroRequired and propertyAreaRequired, and GET /v1/estamp/states/:stateCode/instruments lists the articles for the state with their minimumAmount and, where applicable, allowedAmounts.

Step four, working out the duty, is also yours, and the API is deliberate about that. POST /v1/estamp/duty/calculate takes stateCode, articleCode, optional districtCode and sroValue, and stampDutyAmount. It validates the amount against the state's denominations, minimum and maximum, and returns a priced breakdown: duty untouched, service charges, GST on the service charges, and totalAmount. If a duty rule is configured for the state, requiredDuty appears as a floor you can exceed but not undercut. Everything about how that amount was derived from rent, deposit or valuation stays outside the API.

curl -s -X POST "https://api-b2b.stampmitra.in/v1/estamp/duty/calculate" \
  -H "Authorization: Bearer $STAMPMITRA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "stateCode": "MH", "articleCode": "ART1", "stampDutyAmount": 1000 }'

A rejected amount tells you what is allowed, which is the API doing the denomination part of the job:

{
  "error": {
    "code": "BAD_REQUEST",
    "message": "stampDutyAmount must be one of 100, 200, 500, 1000 for ART1 in MH",
    "requestId": "a1b2c3d4-e5f6-4a1b-8c2d-9f0e1a2b3c4d"
  }
}

The values in that message are illustrative. Build your UI to read the allowed list from the message or from the catalogue and let the user pick, rather than hardcoding denominations.

// Node 18+: decide the duty elsewhere, then let the API validate and price it
async function priceStamp({ stateCode, articleCode, dutyAmount, districtCode, sroValue }) {
  const res = await fetch("https://api-b2b.stampmitra.in/v1/estamp/duty/calculate", {
    method: "POST",
    headers: { Authorization: `Bearer ${process.env.STAMPMITRA_API_KEY}`, "Content-Type": "application/json" },
    body: JSON.stringify({ stateCode, articleCode, stampDutyAmount: dutyAmount, districtCode, sroValue }),
  });
  const body = await res.json();
  if (res.status === 400) return { ok: false, reason: body.error.message }; // show allowed values
  if (!res.ok) throw Object.assign(new Error(body.error?.message), { status: res.status, requestId: body.error?.requestId });
  return { ok: true, total: body.totalAmount, duty: body.stampDutyAmount, fees: body.serviceChargeSubtotal, gst: body.gstAmount };
}

The call is metered, so ask for a quote once the user has confirmed article, state and amount, and cache it. Prices of the call itself are on the pricing page. Statutory duty is passed through at cost and the API fee is separate, which the full e-Stamp flow explains alongside the three wallets that pay for an order.

How should a team decide the duty amount in practice?

Here is a process that works for products that stamp documents for other people, without pretending the software is a lawyer.

1. Classify. Offer a short list of document types your product supports and map each to the article for the state. Keep the mapping in reviewed configuration, owned by someone with legal training, and version it.
2. Collect the measure the article needs. Ask the question that matches the article: total rent and term, agreed price, loan amount. Do not ask for a generic "value".
3. Look up the rule from the authority. Use the state's published schedule, calculator or notification. Record which source and which date you used.
4. Compute the duty with a reviewed function or, better, take the number from the authority's own calculator, and attach the inputs.
5. Round to what can be issued. Check the amount against the allowed denominations and range. The API will tell you if you got it wrong, but you want the user to see this before they pay.
6. Validate and price with the API. Show totalAmount, with duty and fees separated.
7. Show the basis to a human. The user, or a reviewer in your operations team, confirms the article and amount before you create the order.
8. Store the trail. Keep the inputs, the source, the date, who confirmed and the API's response with its requestId.

Steps three and four are where most of the legal risk lives, which is why they are the ones to give to a person or an authorised source rather than to a spreadsheet someone built last year.

What mistakes cause wrong duty?

• Trusting a remembered rate. The rate you remember might be from before a revision, or from a different state.
• Using the wrong article because the document is called something else. Substance beats the title.
• Using the stated price when the state uses the higher of price and valuation. The user's declared figure is not always the measure.
• Reading a slab table the wrong way. Marginal versus whole-amount can change the result materially.
• Ignoring the cap or the floor. Both appear in the schedule, and both change large and small values.
• Forgetting add-ons. Cess, surcharge and registration fee are separate items.
• Treating registration as optional because the stamp exists. Whether registration is needed depends on the document, not on how it was stamped.
• Buying the stamp long before execution. The stamp's date and the document's date are compared.
• Letting the front end choose the cheapest article. That is a compliance failure, and under the service terms a prohibited one.

How StampMitra helps

StampMitra supplies the buying side of stamping: a state-scoped catalogue of articles with the flags that tell you what extra detail a state wants, a validation and pricing call that separates duty from fees and GST, an order flow with review before placement, wallets that pay for duty and fees separately, and certificate delivery. It deliberately does not claim to be the authority on what duty an instrument attracts, which is why the API takes the amount from you and validates it rather than inventing one.

To see the mechanics, get a sandbox key and call the state and article routes, which return a small sample catalogue in sandbox and the live catalogue in production. Read the order flow guide for the developer detail on creation and retries, and the rental agreement use case for how a property platform fits these pieces together. The order creation page and the state and article lookup page cover the next steps in detail, and the authentication reference covers keys. If you are unsure which article or amount applies, take that question to a qualified professional before you build it into code.

API reference at a glance

Frequently asked questions