This guide shows the full arithmetic, how the tax deduction on pre-construction interest really works under the Income-tax Act 2025, and the one tax point most articles get wrong.

What is pre-EMI on a home loan?

On an under-construction flat, the bank does not pay the builder in one go. The RBI has told banks since September 2013 that disbursal of housing loans to individuals should be closely linked to the stages of construction, and that upfront disbursal should not be made for incomplete projects. So the loan is released in tranches as the builder raises demand letters for each stage.

Pre-EMI is the monthly interest on whatever has been released. Kotak's example: ₹5 lakh released at 8.5% means about ₹3,542 a month; when the release reaches ₹15 lakh the pre-EMI rises to ₹10,625. None of it reduces your principal. Your 20-year (or 25 or 30-year) clock starts only when full EMIs begin.

What is full EMI during construction?

Under the full-EMI option, the lender computes a regular EMI on the amount disbursed so far, and the loan tenure is counted from the first disbursement. Each new tranche raises your EMI. By the time the last tranche is released, you are paying almost the same EMI you would pay on a ready flat, and you have already cut the principal a little. Not every lender offers it on every project, so ask at sanction stage.

Worked example: ₹1.2 crore flat, ₹90 lakh loan, 8%

Assumptions. Flat price ₹1.2 crore. Loan ₹90 lakh, which is the RBI maximum of 75% for loans above ₹75 lakh. Rate 8.00% floating, close to HDFC Bank's floor of 8.00% and above SBI's 7.50% after the October 2026 repo hike. Tenure 20 years. Construction 36 months. Tranches: ₹18 lakh each at months 0, 6 and 12, ₹13.5 lakh at months 18 and 24, ₹9 lakh at month 30.

Your own money, either way: ₹30 lakh down payment, about ₹9.1 lakh Karnataka stamp duty, cess and registration (about 7.6%), and ₹6 lakh GST at 5% spread over the instalments.

  • Pre-EMI, month 1: ₹18 lakh × 8% ÷ 12 = ₹12,000.
  • Pre-EMI, month 13 (₹54 lakh out): ₹36,000. Month 31 (₹90 lakh out): ₹60,000.
  • Pre-EMI total over 36 months: about ₹13.86 lakh, all interest.
  • Then full EMI on ₹90 lakh for 240 months: ₹75,280 a month. The loan ends 23 years after the first disbursement.
  • Total paid to the bank: ₹13.86 lakh + (₹75,280 × 240) = about ₹1.95 crore, of which about ₹1.05 crore is interest.
  • Full EMI, month 1: EMI on ₹18 lakh over 240 months = about ₹15,060.
  • Month 13: about ₹45,650. Month 31 onward: about ₹77,110.
  • Total paid during construction: about ₹17.67 lakh, of which about ₹4.16 lakh is principal.
  • Loan ends 20 years after the first disbursement.
  • Total paid to the bank: about ₹1.75 crore, of which about ₹85 lakh is interest.

The difference: full EMI costs about ₹3.8 lakh more during construction (₹17.67 lakh against ₹13.86 lakh) and saves about ₹19.6 lakh in total (₹1.95 crore against ₹1.75 crore). Be clear about where the saving comes from. Most of it is not magic; it is three fewer years of interest, because pre-EMI pushes your entire 20-year repayment clock back by the construction period. If the project is delayed by a year, a pre-EMI borrower pays another year of interest-only payments, about ₹7.2 lakh at full disbursement, without touching the principal.

How is pre-EMI interest treated for tax?

From 1 April 2026 the Income-tax Act, 2025 replaced the 1961 Act. Section 22 of the new Act carries the home loan interest rules that buyers know as Section 24(b). Under it, interest for the period before the property is acquired or constructed is deductible in five equal instalments, starting in the tax year construction is completed and running for the four following years. No interest deduction is available while the flat is still under construction.

The limits under the old regime: for a self-occupied home, the total interest deduction is capped at ₹2 lakh a year, provided construction is completed within five years from the end of the tax year in which you borrowed. If it is not, the cap drops to ₹30,000. Under the default new regime (Section 202 of the 2025 Act), interest on a self-occupied home is not deductible at all.

The tax point most articles miss

For a self-occupied flat, the ₹2 lakh cap applies to the current year's interest plus that year's one-fifth instalment of pre-construction interest, combined. In our example, the first year of full EMIs alone carries about ₹7.13 lakh of interest. That already exceeds ₹2 lakh, so the ₹13.86 lakh of pre-EMI interest adds nothing to your deduction. Paying pre-EMI to 'save tax later' does not work on a home you will live in, at this loan size.

It is different if you will let the flat out. For a let-out property there is no cap on interest set against rent, so the one-fifth instalments (about ₹2.77 lakh a year here) do count under the old regime. Any resulting loss can be set off against salary only up to ₹2 lakh a year, with the rest carried forward. Under the new regime, a house property loss cannot be set off against salary. Principal repayment (Section 123 of the 2025 Act, earlier Section 80C) counts only after construction is complete, so the ₹4.16 lakh of principal repaid during construction under full EMI earns no deduction either.

Which should you choose?

  • Choose pre-EMI if you are paying rent in Bangalore during construction and the full EMI on top of rent would push your outgo above about half your take-home pay.
  • Choose pre-EMI if you plan to sell before or soon after possession and want the lowest carrying cost. Check the builder's transfer rules and fees first.
  • Choose full EMI if you live with family or in your own home, have stable income, and can absorb the rising EMI. It builds equity and ends the loan sooner.
  • Choose full EMI if the project has a long or uncertain timeline. Every month of delay under pre-EMI is pure interest.
  • Middle path: take pre-EMI during construction, then prepay a lump sum at possession. Under the RBI's 2025 pre-payment directions, floating-rate loans to individuals for non-business purposes sanctioned or renewed on or after 1 January 2026 carry no pre-payment charges; see Prepaying Your Home Loan: When It's Worth It.

Checklist before you sign the loan

  • Ask the lender in writing which option they offer on this project and how the EMI changes with each tranche.
  • Get the builder's construction-linked schedule and match it with your cash flow, including GST on each instalment.
  • Check the project on the Karnataka RERA portal: registration, completion date, and quarterly progress. Our guide: How to Read a RERA Project Page, Step by Step: K-RERA, HRERA Gurugram and TNRERA.
  • Keep demand letters, bank disbursement advices and interest certificates. You need them to claim pre-construction interest.
  • Budget for a delay of at least six to twelve months in your pre-EMI plan.

Comparing an under-construction flat with a ready one, including GST? See Under-Construction vs Ready-to-Move in Bangalore: Costs, GST, RERA and Risk Compared (2026), and browse Under Construction, Bangalore or Ready To Move, Bangalore. Our older general explainer is at Pre-EMI vs Full EMI During Construction: Which to Pick.