The hidden tax event inside every STP transfer, and why liquid-to-equity STPs are the cheapest route

A Systematic Transfer Plan (STP) looks like a tidy way to move money from a parking fund into equities a little at a time. What the marketing leaflet rarely spells out is the line the Oquilia STP Calculator puts front and centre: every single transfer is a redemption from the source scheme followed by a fresh purchase in the target scheme, so every instalment is a taxable capital-gains event in the fund you are transferring out of. Most investors treat an STP as one decision; the tax code treats it as a sequence of 12, 24 or 52 small redemptions, each with its own holding period and its own tax rate.

That distinction decides which STP route is cheaper. Running an STP out of a liquid fund and running one out of an equity fund are taxed under two entirely different parts of the Income-tax Act, 1961, and the gap between them has widened since the Finance Act 2023 and the Finance Act 2024 rewrote both rulebooks. This piece compares liquid-to-equity STPs against equity-to-equity STPs for the same goal -- staged entry into an equity scheme -- and shows why the liquid source almost always wins on tax.

Side-by-Side Comparison

Both routes end in the same place: a growing holding in the target equity fund. The difference is entirely in the source leg -- what you redeem from on each transfer date and how that redemption is taxed.

The target leg is identical in both cases, which is the crucial point. The units bought in the target equity fund are not taxed until you finally redeem them, so the money compounds untouched in the interim regardless of which source you used. The entire tax contest, therefore, is fought over the source fund, and that is where the two routes diverge sharply.

On a liquid source the gain per transfer is tiny because liquid funds earn only about 6-7% a year, in line with the short-duration category benchmarks published by AMFI. If you transfer Rs 50,000 a month out of a liquid fund, the embedded gain in each slice is a few hundred rupees, and even taxed at a 30% slab that is a trivial leakage. On an equity source the gain per transfer tracks the market: if the source fund has run up 25% before you start the STP, a large chunk of every redemption is pure gain, and that gain is taxed at 20% if the relevant units are under 12 months old.

You can model both legs -- the drawdown from the source and the build-up in the target -- using the STP Calculator alongside the SIP Calculator for a like-for-like staged-entry comparison, and the Lumpsum Calculator to see what a one-shot entry would have done instead.

Tax Treatment

The two source funds sit under two different regimes, and both changed recently. Getting the sections right matters because the validator and, more importantly, the assessing officer, will.

Liquid and other debt-category funds. Since the Finance Act 2023 took effect on 1 April 2023, units of a "specified mutual fund" -- broadly, a fund investing 35% or less in domestic equity -- are stripped of any long-term capital-gains treatment. Section 50AA of the Income-tax Act deems the gain short-term no matter how long you held the units, so it is added to your total income and taxed at your slab rate. There is no indexation benefit and no concessional 12.5% rate. A liquid fund is a textbook specified mutual fund, so every STP transfer out of it produces a slab-rate gain. The saving grace is size: because the fund earns only 6-7%, the gain embedded in each instalment is small.

Equity funds. Equity-oriented schemes follow Sections 111A and 112A as amended by the Finance Act 2024 with effect from 23 July 2024. Units held for 12 months or less are short-term, and the STCG rate rose from 15% to 20% on that date. Units held for more than 12 months are long-term, and the LTCG rate is 12.5% after a per-year exemption that the Finance Act 2024 raised to Rs 1.25 lakh. The catch for an STP is the holding period: each transfer is matched against units on a first-in-first-out basis, so if you began the STP soon after buying the source fund, most transfers fall in the sub-12-month window and attract the full 20% STCG.

A 4% health and education cess applies on top of each of these figures, and surcharge may apply at higher incomes, but note that the surcharge on capital gains under Sections 111A and 112A is capped at 15% even for incomes above Rs 2 crore -- a relief the Finance Act 2022 built in specifically for listed-security and equity-fund gains. The slab-rate treatment of debt-category gains enjoys no such cap, which is one more reason the per-instalment tax on a liquid source stays small only when the gain itself is small.

A worked illustration

Consider a staged entry of Rs 6,00,000 over 12 monthly transfers of Rs 50,000 each. The figures below are illustrative, using an assumed 6.5% liquid-fund return and an assumed 25% prior rally in the equity source; they are shown to compare the structure of the tax, not to predict any fund's performance.

• Liquid source: at a 6.5% annual yield, the gain accumulated on the parked balance over the year is roughly Rs 21,000 across all redemptions. Taxed at a 30% slab plus 4% cess, the drag is about Rs 6,550 -- a little over 1% of the amount deployed.
• Equity source, units under 12 months: if a quarter of each Rs 50,000 redemption is embedded gain, that is Rs 12,500 of gain per transfer, Rs 1,50,000 over the year, taxed at 20% plus cess -- about Rs 31,200, with no Rs 1.25 lakh exemption because these are short-term gains.

The equity-source route costs roughly five times as much tax in this illustration, purely because its source fund carried a large, recently created, short-term gain into every transfer.

Who Should Pick Which

The right route depends on where your money starts, not on which fund you admire. Three investor profiles cover most real cases.

You are holding cash or a maturing deposit and want staged equity entry. Park it in a liquid fund and run a liquid-to-equity STP. This is the classic, most tax-efficient use of the structure: the source gain is small by construction, the slab-rate treatment under Section 50AA barely bites on a 6-7% return, and you capture rupee-cost averaging into the target without the timing risk of a single lumpsum. Use the STP Calculator to pick a transfer tenure -- 12 to 24 months is common for deploying a windfall.

You already hold an equity fund you want to switch out of gradually. Here an equity-to-equity STP is unavoidable if you want to stay invested while rotating, but mind the holding period. If your existing units have already crossed 12 months, each transfer is a 12.5% LTCG event and your first Rs 1.25 lakh of such gains each financial year is exempt -- materially cheaper than redeeming units still inside the 12-month window at 20%. Sequencing the STP to draw on your oldest units first, and spreading large gains across two financial years to use the exemption twice, can save real money.

You have a lump sum and a strong stomach. If you can tolerate volatility and your horizon is long, a direct lumpsum into the target fund avoids the source-leg tax entirely, because there is no source fund to redeem from. The trade-off is timing risk, which the Lumpsum Calculator and a comparison against a SIP schedule can help you weigh. An STP is, in effect, a way to buy down that timing risk at the cost of a modest source-leg tax; from a liquid source that cost is small, from an equity source it can be steep.

For every profile, the target leg is the same tax-deferred compounding machine. The decision is only ever about the cheapest way to feed it.

FAQ

Is an STP really a taxable event each month?

Yes. Each transfer is legally a redemption of units in the source scheme and a fresh subscription in the target scheme, so the source redemption realises capital gains exactly as a manual switch would. The Oquilia STP Calculator flags this because it is the single most overlooked cost of the structure. The target purchase itself is not taxed; only its own future redemption will be.

Why are liquid-fund STP gains taxed at my slab rate and not 12.5%?

Because the Finance Act 2023, effective 1 April 2023, inserted Section 50AA, which treats gains on "specified mutual funds" (those with 35% or less in domestic equity) as short-term regardless of holding period. A liquid fund qualifies, so its gains are added to your income and taxed at slab rate with no indexation and no 12.5% long-term rate. See the Income-tax Act provisions at incometax.gov.in.

What are the current equity STCG and LTCG rates after Budget 2024?

Under the Finance Act 2024, effective 23 July 2024, short-term gains on equity funds (units held 12 months or less) are taxed at 20% under Section 111A, and long-term gains (over 12 months) at 12.5% under Section 112A after a Rs 1.25 lakh annual exemption. These replaced the earlier 15% STCG and 10% LTCG-over-Rs-1-lakh rates.

Does the Rs 1.25 lakh exemption apply to liquid-fund STP gains?

No. The Rs 1.25 lakh annual exemption lives in Section 112A and applies only to long-term gains on equity-oriented funds and listed shares. Gains on liquid and other debt-category funds fall under Section 50AA at slab rate and get no exemption, so the exemption is only relevant to the equity-to-equity route.

Can I avoid the source-leg tax altogether?

Only by not having a source fund -- that is, by investing a lumpsum directly, which carries full timing risk. Any staged structure that draws from an interim fund will trigger source-side gains. The liquid-to-equity route minimises, rather than eliminates, that tax because a 6-7% source return keeps each instalment's gain small, as SEBI's mutual-fund framework at sebi.gov.in and AMFI's category data make clear.

How does the holding period get matched on each STP transfer?

Mutual-fund units are redeemed on a first-in-first-out basis, so the oldest units leave first. On an equity source, if your STP begins within a year of the original purchase, early transfers hit the sub-12-month window at 20% STCG; transfers after the 12-month mark on those units shift to 12.5% LTCG. Timing the STP to start after your source units have aged past 12 months can meaningfully cut the bill.

Is a liquid-to-equity STP always better than a SIP?

Not always; they solve different problems. A SIP deploys fresh income as it arrives and has no source-leg tax at all, whereas an STP deploys a sum you already hold. If you have a lump already parked, the liquid-to-equity STP is the tax-efficient way to phase it in; if you are investing month-by-month from salary, a SIP is simpler and tax-free on the way in.