How-to call option option writing short call SPAN margin physical settlement Kite

How to sell a call option on Zerodha Kite

From WebNotes, a public knowledge base. Last updated 21 June 2026. Reading time ~12 min. Level: Advanced.

Key facts

Order type to write a call	Sell-to-open, product NRML (overnight) or MIS (intraday), on the NFO segment in Kite
Margin blocked	Full SPAN plus exposure margin; exposure for index option selling is 2% of contract value, 3.5% for stock options (NSE Clearing)
Premium	Credited to your account, but only the next trading day in the live account; the margin calculator shows it reducing the blocked amount
Maximum loss on a naked short call	Theoretically unlimited; the spot can rise without a ceiling
Stock-call settlement on ITM expiry	Physical: you must deliver the shares, so a short call needs delivery margin in the expiry week

Procedure

Confirm the F&O segment is active and margin is fundedActivate the F&O segment on your Zerodha account and ensure sufficient funds, since writing a call blocks the full SPAN plus exposure margin upfront, not just the premium.
Find the call contract on KiteSearch the call contract on the NFO segment by underlying, expiry and strike in the Kite search bar and add it to your marketwatch or open the option chain.
Open the sell order formClick Sell to place a sell-to-open order. Choose product type NRML to carry the position overnight, or MIS for an intraday short that is auto-squared-off.
Read the margin and premium display before confirmingReview the required SPAN plus exposure margin and the premium the order will credit. Confirm the margin is available; a shortfall triggers a penalty.
Place the order and confirm the short positionSubmit the order. On execution the premium is credited (reflected in the live account the next trading day) and the trade appears as a short call in Positions.
Manage or square off before expiryMonitor the position and buy back the same contract to square off. Do not let an in-the-money short stock call run to expiry, since it converts into a physical-delivery obligation.

Writing a call option means selling a contract you do not own, collecting the premium, and taking on the obligation to deliver the underlying at the strike price if the buyer exercises. On Zerodha Kite this is a sell-to-open order on the NFO segment, and it is one of the highest-risk trades a retail account can place. The writer’s gain is capped at the premium received; the loss on a naked (unhedged) short call is theoretically unlimited, because the spot price can rise without a ceiling.

This guide covers the exact order on Kite, the SPAN plus exposure margin Zerodha blocks before it accepts the order, when the premium actually reaches your account, the physical-settlement trap on single-stock calls, and how to square off. Read it alongside naked option selling margin on Zerodha for the capital arithmetic and the SEBI study on retail F&O losses before you decide the trade is worth the risk. SEBI’s FY2024 study found about 91% of individual derivatives traders lost money, with an aggregate net loss near Rs 75,000 crore.

Conflict-of-interest disclosure. This guide is published by the WebNotes Editorial Team for informational purposes and is written independently. WebNotes operates a Zerodha account-opening referral programme, disclosed on the pages that carry the referral link; this guide does not carry it and earns no referral commission from the procedure described here.

Step-by-step procedure

The procedure infobox at the top of this guide lists the sequence as structured steps. The H3 sections below expand each one, with the order-form fields, the margin display, and the failure modes that catch first-time option writers.

1. Confirm the F&O segment is active and margin is funded

Writing options needs the F&O segment enabled on your account. Activate it from Console under Account then Segments if it is not already on; income proof may be required. Unlike buying an option, where you only pay the premium, writing a call blocks the full SPAN plus exposure margin upfront. Fund the account with cash, or pledge holdings for collateral, before you place the order. Note the 50:50 cash-collateral rule : at least half the margin must sit as cash or cash-equivalent, so pure collateral will not carry a short option on its own.

2. Find the call contract on Kite

Press the search key in Kite and type the underlying, for example NIFTY for the index or RELIANCE for a stock. Select the NFO exchange rows, then pick the expiry, the strike, and the call leg, which Kite labels CE (Call European). A contract reads as NIFTY 26JUN 25000 CE: Nifty, the 26 June expiry, the 25000 strike, a call. All NSE equity and index options are European-style, exercisable only at expiry, not before. Add the contract to a marketwatch slot.

3. Open the sell order form

Hover over the contract and click S to open the sell order form. Selling here means sell-to-open: you are creating a new short position, not closing an existing long. The form defaults matter:

Product: NRML to hold the short overnight or to expiry; MIS for an intraday-only write that auto-squares before the cut-off.
Order type: Limit, set near the current bid. A market order on a wide option spread, common on out-of-the-money strikes and far expiries, can fill far below the last traded price and shrink the premium you collect.
Quantity: in lots. Confirm the lot size, since the Nifty lot is 75 after the October 2024 revision and the exposure scales with it.

4. Read the margin and premium display before confirming

For a sell order, the order form shows the margin required, not a premium outflow. This is the SPAN plus exposure figure the position will block. The premium you receive is shown separately as a receivable. The arithmetic that trips people up: the displayed margin used is the gross SPAN plus exposure, and the premium credit only partly offsets it. For one naked Nifty short call near the money you might see roughly Rs 1.5 lakh to Rs 2 lakh blocked per lot, against a premium of a few thousand rupees. Read option premium credit on Kite funds for how the credit and the block interact on the funds page.

5. Place the order and confirm the short position

Click Sell, review the confirmation modal showing the instrument, side, quantity, price, and estimated margin, and submit. A limit order sits in the exchange order book until the market trades at your price; a filled order moves to Positions, where the short call shows as a negative quantity. The position P&L runs against you as the option premium rises and in your favour as it falls.

6. Manage or square off before expiry

To close, buy back the same contract. No fresh margin is needed to square off a short, provided you hold no pending order on that contract; a stray pending order is read as a new position and demands margin. On a profitable short, the buy-back still shows as a cash debit, because you are paying to repurchase the option you sold; the realised profit is the premium received minus the buy-back cost. For an in-the-money short stock call, square off before the expiry-day cut-off to avoid physical delivery, covered below.

Margin: why a naked short call is capital-intensive

Zerodha blocks the full SPAN plus exposure margin on a naked short call because there is no offsetting position to cap the worst-case loss. SPAN, the exchange’s Standard Portfolio Analysis of Risk engine, sizes the margin to the maximum probable one-day loss on the contract and revises it through the day. Exposure margin is charged on top: NSE Clearing sets it at 2% of contract value for index option selling and 3.5% for stock option selling. The contract value is spot price times lot size, so for a Nifty contract around 25000 with a 75 lot, the notional is about Rs 18.75 lakh, and the exposure slice alone is near Rs 37,500.

Component	Naked short index call (Nifty, one lot)	Basis
SPAN margin	About Rs 1.1 lakh to Rs 1.5 lakh	NSE SPAN engine, revised intraday
Exposure margin	About 2% of contract value	NSE Clearing exposure rate for index option selling
Total margin blocked	About Rs 1.5 lakh to Rs 2 lakh	SPAN plus exposure, the NRML overnight margin
Premium received	Credited next trading day	Zerodha funds settlement, T+1

The figures move with spot, volatility, and the strike, so confirm the live number on the Zerodha margin calculator before every trade. Two add-ons raise it further: additional margin for selling index options that SEBI and the exchanges layer on, and higher margin near expiry as exchanges raise rates into the expiry session. A hedged short call, where you also buy a higher call, qualifies for exposure margin relief and blocks a fraction of the naked figure; the naked structure forfeits that benefit entirely.

The premium: credited, but settled T+1

When you write the call, the premium is credited to your trading account, but in the live account it reflects only the next trading day, even though the margin calculator nets it against the blocked amount the moment you model the trade. So the cash you can redeploy lags the trade by a day. The credit counts toward the cash component of your F&O margin, which helps option sellers running several shorts meet the 50:50 cash requirement . For the funds-page mechanics, see option premium credit on Kite funds .

A point that confuses new writers: a profitable short call still shows a debit when you buy it back. You sold the option to open and must repurchase it to close, so the buy-back is always a cash outflow. The trade is profitable when that outflow is smaller than the premium you took in. See option premium for why the buy-back debit and the net profit are not the same number.

Unlimited-loss risk on a naked call

A short call’s payoff is the mirror of a long call’s. The buyer profits as the underlying rises above the strike plus premium, and the spot has no ceiling, so the writer’s loss has no floor. Your maximum gain is the premium; your maximum loss is unbounded. This is the structural reason naked short calls dominate the tail of retail F&O losses: a single gap-up on the underlying, an earnings surprise on a stock, or a sharp index rally can hand a writer a loss many times the premium collected. SEBI’s FY2024 study put aggregate individual-trader net losses near Rs 75,000 crore, with about 91% of participants in the red, and tightened participation through the F&O entry-barrier rules of 2024 partly in response. The defence is structural: convert the naked call into a call spread by buying a higher strike, which caps the loss at the gap between strikes and slashes the margin. Many option sellers track only theta decay and ignore this tail entirely.

Physical settlement on an in-the-money stock call

All single-stock options on the NSE are compulsorily physically settled at expiry; index options on Nifty and Sensex are cash-settled. The distinction is decisive for a short call. If your short stock call is in the money at expiry, you are obliged to deliver the underlying shares at the strike price, which means selling the full lot of shares you may not hold. Zerodha ramps up delivery margin through the expiry week on positions heading for physical settlement, issues email and SMS alerts when a stock option moves into the money, and the obligation crystallises at the 3:30 PM expiry-day cut-off.

The trap is that an out-of-the-money short stock call early in the expiry week can drift into the money by Thursday and convert a small premium trade into a delivery obligation worth many lakhs of contract value. STT compounds it: the exercise STT is levied on the intrinsic value, currently 0.15% on exercised options after the 1 April 2026 Budget hike, up from 0.125% under the October 2024 regime. For the mechanics and the close-before-expiry advice, see physical settlement of stock F&O , how to physically settle an ITM option , and how to avoid physical settlement . The do-not-exercise facility has been largely withdrawn after the close-to-money rules changed, so a writer cannot rely on it; see the do-not-exercise option .

Charges and STT on a written call

Zerodha charges a flat Rs 20 brokerage per executed order on options, regardless of size, on both the sell-to-open and the buy-to-close legs. On top sit STT, exchange transaction charges, GST, SEBI turnover fees, and stamp duty. STT on the sale of options is charged on the premium: currently 0.15% on the sell side, raised from 0.1% by the 1 April 2026 Budget. On an exercised in-the-money option the STT is 0.15% of the intrinsic value, the figure that can swamp a thin profit and is the standing reason to close in-the-money positions before expiry rather than let them exercise. For the full breakdown see Zerodha F&O charges and options exercise charges on Zerodha . The realised P&L from writing options is taxed as F&O business income; see F&O taxation in India .

What can go wrong

Treating the premium as free cash on trade day. The premium credits to your account but settles only the next trading day in the live account. Do not redeploy it intraday.
Underestimating the margin. A naked short call blocks the full SPAN plus exposure margin, often Rs 1.5 lakh to Rs 2 lakh per Nifty lot, and rises near expiry. Check the margin calculator before ordering.
Ignoring physical settlement. A short stock call that is in the money at expiry obliges you to deliver shares. Square off before the expiry-day cut-off if you cannot deliver.
A market order on a wide spread. Out-of-the-money and far-expiry calls have wide bid-ask spreads; a market sell can fill well below the last price. Use a limit order.
A stray pending order on square-off. Squaring off a short needs no fresh margin, but a pending order on the same contract is read as a new position and demands margin, blocking the exit.
Running naked into a known event. An earnings date, a results announcement, or a policy event can gap the underlying through your strike overnight, when you cannot square off.

External references

References

Zerodha support, How is the margin calculated for selling options? (as of 21 June 2026): full SPAN plus exposure margin, premium credited next trading day.
NSE Clearing, SPAN and exposure margin framework: exposure margin 2% of contract value for index option selling, 3.5% for stock option selling.
Zerodha charges, zerodha.com/charges (as of 21 June 2026): STT 0.15% on options sell side on premium, 0.15% on intrinsic value of exercised options, flat Rs 20 brokerage per executed order, effective 1 April 2026 per Budget 2026-27.
SEBI, Study on profit and loss of individual traders in the equity F&O segment, FY2024: about 91% of individual traders incurred net losses.
NSE, Physical settlement of stock derivatives: all single-stock options compulsorily physically settled at expiry.

Frequently asked questions

How much margin does Zerodha block to sell one call option?

The full SPAN plus exposure margin. For a single naked Nifty short call this runs roughly Rs 1.5 lakh to Rs 2 lakh per lot. Exposure margin alone is 2% of contract value for index options and 3.5% for stock options, per NSE Clearing.

Do I receive the premium immediately when I write a call?

The premium is credited to your trading account, but in the live account it reflects only the next trading day. The Zerodha margin calculator shows the premium reducing the blocked amount, yet the cash itself settles T+1.

What is the maximum loss when I sell a naked call?

Theoretically unlimited. A call buyer profits as the underlying rises, and there is no ceiling on the spot price, so the writer’s loss grows without bound. The premium received is the only gain, capping the upside at that figure.

What happens if my short stock call expires in the money?

All single-stock options on the NSE are physically settled. An in-the-money short call obliges you to deliver the shares at the strike. Zerodha ramps up delivery margin through the expiry week and alerts you by email and SMS.

Can I square off a short call any time before expiry?

Yes. Buy back the same contract to close the position. No fresh margin is needed to square off, provided you have no pending order on that contract. The blocked SPAN plus exposure margin is released on exit.

Is writing a call option a good income strategy for a small account?

Rarely. The margin is capital-intensive and the tail risk is unlimited. SEBI’s study found about 91% of individual F&O traders lost money in FY2024. A defined-risk spread caps the loss and frees far more capital than a naked short call.

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WebNotes Editorial Team

The WebNotes Editorial Team covers Indian capital markets, payments infrastructure and retail investor procedures. Every article is fact-checked against primary sources, principally SEBI circulars and master directions, NPCI specifications and the official support documentation published by the intermediary in question. Drafts go through a second-pair-of-eyes review and a separate compliance read before publication, and revisions are tracked against the SEBI and NPCI rule changes referenced in the methodology section.

Last reviewed: 21 June 2026
Conflicts of interest: WebNotes is independent. No relationship with any broker, registrar or bank named in this article.