Where a corporation's property-tax formula is publicly documented, this page's calculator already runs it. What official sources add beyond the formula is the fine print that decides the actual bill: BBMP's own FAQ sets depreciation, a 5% early-payment discount and 2% monthly penal interest on old arrears; MCGM's RTI manual values a terrace, mezzanine or loft at a fraction of the flat's rate rather than at zero; and letting the flat changes not only the corporation's rate but also, separately, how the rent itself is taxed.
Bengaluru: depreciation, the early-payment discount, and what a late payment costs
BBMP's own FAQ on the Unit Area Value scheme (bbmptax.karnataka.gov.in) adds three mechanics the calculator's headline formula does not surface on its own. First, depreciation is available under UAV, computed on a calendar-year basis and claimable only once per block period — so a re-assessment resets the depreciation clock rather than compounding it every year. Second, a taxpayer who pays at the prescribed rate within the early-payment window gets a 5% discount off that year's tax; miss the block period entirely and arrears predating 2016-17 carry 2% penal interest a month, not a flat annual penalty. Third, where car-park area is billed separately from the flat's built-up area, BBMP charges it at 50% of the zone-and-occupancy rate rather than the full rate — worth checking on a flat sold with an explicitly metered covered-parking slot.
Mumbai: what a terrace, mezzanine or loft actually adds to the capital value
MCGM's capital-value formula (CV = Base Value × User Category × Nature/Type of Building × Age Factor × Floor Factor × Carpet Area) is documented in the corporation's own RTI manual (Assessment and Collection Department, Manual V, Chapter 6), and the same manual prices the three extra spaces a Mumbai flat often carries. An open terrace in exclusive possession is valued at 20% of the flat's base-value rate if it belongs to a residential unit, or 50% if non-residential. A mezzanine floor is valued at 70% of the base rate applied to the flat beneath it, and a loft or attic floor at 50%. None of the three is charged at the flat's own full rate, and none is free — a mezzanine or loft that a buyer treats as bonus space still adds to the capital value, just at a discount to the main floor.
The same manual applies a parallel formula to open land — CV = Base Value × User Category × permissible FSI × Area of Land — which is why a plot and a built flat on the same base-value street are not comparable on a per-square-foot basis: one formula runs on carpet area and a floor factor, the other on approved FSI. The manual states the capital-value formula and its base-value source (the Stamp Duty Ready Reckoner); it does not itself publish the final tax-rate percentage MCGM applies to that computed capital value, so no rate figure is stated here beyond what the formula multiplies.
Chennai: nursing homes and star hotels are not taxed like flats
Greater Chennai Corporation's own tax-assessment page (chennaicorporation.gov.in) states that while ordinary residential and commercial property is taxed as a percentage of the reasonable-letting-value-derived annual rental value, two special property types use a different base entirely: a nursing home is charged at 13.5% of its annual room-tariff-based income, and a star hotel at 10% of annual room tariff. Neither runs through the ₹9.92 common-factor annualisation or the grade table that a residential flat uses — a mixed-use building with a clinic or a budget hotel on the ground floor is not a single GCC calculation.
Letting a flat changes two bills, not one
The calculator above already shows that BBMP, and several other corporations, bill a tenanted flat at a different rate from a self-occupied one. What it does not show — because it is an income-tax question, not a municipal one — is that letting also changes how the loan interest on that flat is treated. Under the old tax regime, the Income Tax Department's own AY 2026-27 guidance (incometax.gov.in) caps the Section 24(b) interest deduction at ₹2,00,000 a year for a self-occupied property, but places no such cap on a let-out property's interest. Under the new (default) regime, the department's own regime-comparison FAQ (incometax.gov.in) states plainly that Section 24(b) interest on a self-occupied property is not allowed at all, and that Section 80C — the ₹1,50,000 combined limit that includes principal repayment — cannot be claimed either. A landlord weighing whether to let a flat is not just re-running the corporation's tenanted-rate formula; they are also deciding, or discovering by default, which regime's interest treatment applies to the loan that bought it. Work out which regime you are in, and what the loan interest is worth under it, on the home loan tax benefit calculator; once you have the annual property tax figure from the corporation you actually bill to, it becomes an input on the rental yield calculator if the flat is let.
Methodology
Corporation figures are read from each authority's own published FAQ, RTI manual or tax-assessment page, checked 21 September 2026 (see sources). Income-tax figures are read from the Income Tax Department's e-filing portal for AY 2026-27. Neither GHMC's, MCD's nor PMC's property-tax formula is independently verified from a primary source at time of writing, which is why this page's calculator and this article name those three corporations without a formula, rather than publishing a widely circulated but unconfirmed one.
Sources
- BBMP — Frequently Asked Questions (Unit Area Value / SAS) — accessed 2026-09-21
- MCGM — RTI Manual V, Chapter 6, Capital Value System — accessed 2026-09-21
- Greater Chennai Corporation — Property Tax Assessment — accessed 2026-09-21
- Income Tax Department — Salaried Individuals, AY 2026-27 — accessed 2026-09-21
- Income Tax Department — New vs Old Tax Regime FAQs — accessed 2026-09-21