Home loan prepayment vs SIP — where should extra ₹10K/month go?

You have a ₹40 lakh home loan running at 7.75%, EMI of ₹35,460, and ₹10,000 extra every month after expenses. Two voices in your head: "Crush the debt" vs "Compound it in equity". The internet says SIP wins because 12% beats 7.75%. The internet skips half the math.

The naive comparison

Outstanding ₹40L, remaining tenure 18 years, rate 7.75%. You have ₹10,000/month extra for 18 years.

Strategy	What you end with
Pay ₹10K/mo extra into loan	Loan closes in ~12.5 years. Save ₹14.8L interest. Then EMI + ₹10K = ₹45K free for next 5.5 years → invest at 12% → ₹39L corpus.
Invest ₹10K/mo in SIP at 12%	Loan finishes on original 18Y schedule. SIP corpus after 18 years = ₹76L.

On paper, SIP wins by ₹37L. The handwave answer: "obviously SIP." Now we add reality.

Reality 1 — tax slashes both sides differently

A 7.75% loan rate is not 7.75% effective if you're in the old regime. Section 24(b) lets you deduct up to ₹2 lakh of interest annually. At 30% slab, that deduction is worth ₹60K/year. On a ₹40L loan in year 1, you pay roughly ₹3L interest — ₹2L is deductible — so the post-tax loan cost is closer to 6.25%.

In the new regime (default for FY 2026-27), there is no interest deduction on a self-occupied home. Your 7.75% loan stays 7.75%.

SIP also gets taxed — equity LTCG is 12.5% on gains over ₹1.25L per year. A ₹76L SIP corpus with ₹54L gain → ₹6.4L LTCG tax. Net in hand ≈ ₹70L (assuming no harvesting).

Reality 2 — the apples-to-apples table

Same ₹10K/month for 18 years, ₹40L loan, 7.75% rate, post-tax:

Borrower	Effective loan cost	Prepay outcome (loan + post-prepay SIP)	SIP outcome (net of LTCG)	Winner
Old regime, 30% slab, full ₹2L interest claimed	~6.25%	₹38L (corpus from 5.5Y SIP)	₹70L	SIP by ₹32L
New regime (no deduction)	7.75%	₹38L	₹70L	SIP by ₹32L
SIP returns just 10% (not 12%)	7.75%	₹38L	₹54L	SIP by ₹16L
SIP returns 8% (debt fund / disappointment)	7.75%	₹38L	₹42L	SIP by ₹4L only

The 12% SIP return is a historical average over very long periods. Plenty of 5-year and 10-year windows in Indian equity have returned 6–9%. The "obvious SIP win" gets thin fast if you assume realistic-but-cautious returns.

Reality 3 — risk is not symmetric

• Loan prepayment is guaranteed. Every ₹10K you prepay returns exactly the loan rate, every time, no volatility.
• SIP has sequence-of-returns risk. A 30% drawdown in year 16–17 right before you'd planned to deploy that corpus can wipe years of compounding. EMI doesn't pause for bear markets.
• Loan is leverage. If you lose your job in year 8, the loan still expects EMI. A bigger SIP corpus + bigger remaining loan is more fragile than a smaller corpus + smaller remaining loan.

The decision framework — actually useful

Pick prepayment if any of these is true:

• Your loan rate is ≥ 9.5% (current personal loan / gold loan / older home loan that didn't get repriced)
• You're in the new regime, AND your job/income is volatile (freelancer, commission-based, single-income household)
• You have fewer than 5 years left on the loan (interest component is tiny now; psychological win matters more than math)
• You can't sleep with debt outstanding (this is a real, valid reason — financial peace ≠ spreadsheet maximisation)
• You don't already have a 6-month emergency fund (build that first, before either option)

Pick SIP if any of these is true:

• Your loan rate is ≤ 8.5%, your remaining tenure is 12+ years, and you can ride a 30–40% drawdown without panic-selling
• You're in the old regime and getting the full ₹2L Section 24(b) deduction (post-tax loan cost falls to ~6%)
• You're salaried with stable income and want long-term wealth, not just debt closure
• Your loan is more than 8 years away from closure (the rate gap × time gap is too large to ignore)

The hybrid that wins for most people

The split nobody recommends but works for the messy middle:

• 50% of the extra ₹10K → SIP (₹5K in a Nifty 50 index or flexi-cap fund). Captures equity upside.
• 50% → annual lump-sum prepayment (₹60K once a year into the loan). Cuts tenure ~3 years on a 20Y loan and saves ~₹8L interest. Also feels great.

Why this works: you stop optimising on a single number and instead get partial debt reduction + partial equity exposure. After 5–6 years your loan principal is meaningfully lower, the SIP has built a buffer corpus, and you've never been over-exposed to one side.

What about loan tenure reduction vs EMI reduction on prepayment?

When you prepay, the bank will ask: reduce EMI or reduce tenure? Always pick reduce tenure. Same EMI for fewer months means more total interest saved. Reducing EMI is a comfort trap — you "feel" lighter but pay more interest over time.

The behavioural test

Honest question: in March 2020 when the Sensex fell 38% in five weeks, would you have stopped your SIP, kept it running, or increased it? If your answer is "stopped" — pick prepayment. Math doesn't matter if you can't execute the plan.

Run your own numbers

Use our EMI calculator to see how much interest a ₹10K/month extra payment saves on your specific loan. Then compare against an SIP projection at 10% (realistic, not optimistic) over the same period. Apply your tax regime. The right answer for you falls out of the table.

FAQs

Should I prepay my home loan or invest in PPF for the same tax benefit?

PPF gives you 7.1% tax-free and 80C deduction. Home loan principal repayment also counts for 80C (up to ₹1.5L). You can only use ₹1.5L of 80C once — so PPF + home loan principal compete. If your home loan principal already maxes 80C (typical above ₹15L outstanding), put extra into PPF. If not, do both.

What if my loan is on a fixed rate?

Fixed-rate loans often carry 2–4% foreclosure / prepayment penalty. Calculate: penalty + tax loss vs interest saved. Usually prepayment doesn't pay off on fixed loans — SIP wins more easily. Floating-rate retail loans have zero foreclosure fee (RBI rule).

Is part-prepayment better than full prepayment?

Part-prepayments compound. ₹1L extra in year 2 of a 20-year loan saves more interest than ₹1L extra in year 15. Spread small extras early rather than saving for one big lump-sum later.

Should I break my FD to prepay the loan?

If FD rate < (post-tax loan rate), yes. ₹10L FD at 7% taxable (30% slab) = 4.9% post-tax. Loan at 7.75% costs more. Mathematically break FD. But keep the 6-month emergency fund untouched.

Does prepayment hurt my CIBIL score?

No. Prepayment is reported as on-time / advance payment and either holds or improves your score. Full closure removes one tradeline, which can briefly nudge the score down 5–10 points, but it recovers within 2–3 months.

What about taking a top-up loan to invest in equity?

Don't. Top-up loans run 9–10.5%, no interest deduction (since funds aren't for the property), and you're now leveraged into a volatile asset. The math only works on paper.