Kolkata property tax under KMC's unit area assessment: the formula, a worked bill, and mutation after you buy

Rules and rates as of 25 October 2026.

Buy a flat in Kolkata and two separate offices need to hear about it. The registration office records the sale. The Kolkata Municipal Corporation (KMC) separately records who pays property tax, and how much. That second step, mutation, is easy to forget. The tax figure is no longer a negotiated "annual rental value". Since 2017 the city has used a formula you can work through yourself.

Unit area assessment in one paragraph

KMC's Unit Area Assessment (UAA) scheme was published in the Official Gazette on 1 April 2017, according to the corporation's own UAA page. It covers wards 1 to 141. Each street stretch in the city is placed in one of seven categories, A to G. Each category carries a Base Unit Area Value (BUAV), a notional annual value per square foot. Your property's annual value is that BUAV multiplied by your covered space and by five "multiplicative factors". The tax is a flat percentage of that annual value. KMC says the categories and values are to be revisited once every five years, and the tax rate must stay within a band of 6% to 20%.

The pieces of the formula

KMC's Self-Assessment Form sets out the inputs:

• BUAV (₹ per sq ft per year): A ₹74, B ₹56, C ₹42, D ₹32, E ₹24, F ₹18, G ₹13. Category E includes recognised refugee colonies and EWS settlements; G covers slum, bustee and thika-tenanted land. Your category depends on the street your building stands on, as listed in KMC's final notification on blocks and categories.
• Covered space: the total floor area including wall thickness, plus balconies, verandahs, covered garages and staircases. Where several flats share a staircase, its area is shared out among them. If this measured area differs from the area in your registered deed, the form says the higher figure generally applies.
• Age factor: 1 for a building up to 20 years old, 0.9 for 20 to 50 years, 0.8 above 50.
• Location factor, by the width of the road the property abuts: 0.6 up to 2.5 m, 0.8 up to 3.5 m, 1 up to 12 m, and 1.2 above 12 m.
• Occupancy, structure and usage factors. Separate codes cover owner-occupied versus tenanted (tenanted values vary with the age of the tenancy), pucca versus semi-pucca, and residential versus shop, office and so on. Apartments larger than 2,000 sq ft, excluding parking, have their own structure code.

The tax rates the form lists are 15% where the annual value is under ₹30,000 and 20% for others, with lower rates for bustees and government property. In some wards a small Howrah Bridge tax (0.5% or 0.25% of annual value) is added. In wards 101 to 114 there is none.

A worked example

Take a 10-year-old, owner-occupied flat with 1,050 sq ft of covered space, on a 9-metre road in a Category C stretch, in a ward that pays the 0.5% Howrah Bridge tax. We assume the occupancy, structure and usage factors for an owner-occupied, pucca, residential flat are each 1. That is how KMC's own worked examples treat them, but the factor table in the form we read was not legible, so check your figures against the KMC demand.

• Annual value = 1,050 × ₹42 × 1 (age) × 1 (location) × 1 × 1 × 1 = ₹44,100 (the form rounds to the nearest ₹10)
• Tax rate: 20%, since ₹44,100 is above ₹30,000. Property tax = ₹44,100 × 20% = ₹8,820 a year
• Howrah Bridge tax = ₹44,100 × 0.5% = ₹220.50 a year
• Quarterly bill, per the form's formula = ₹44,100 × (20 + 0.5) ÷ 100 ÷ 4 = ₹2,260.13, rounded to ₹2,260
• Paid by each quarter's due date, with the 5% rebate: ₹2,260 × 0.95 = ₹2,147 a quarter, or ₹8,588 a year
• All four quarters paid together within the first quarter's rebate period (5% on Q1, 10% on Q2 to Q4): ₹2,147 + 3 × ₹2,034 = ₹8,249

How each factor moves the bill

Here is the same 1,050 sq ft flat with one input changed at a time. The figure is the yearly property tax before the Howrah Bridge tax and any rebate.

Change from the example	Annual value	Rate	Property tax a year
Example flat (Category C, 9 m road, 10 years old)	₹44,100	20%	₹8,820
Category A street instead	₹77,700	20%	₹15,540
Category E street instead	₹25,200	15%	₹3,780
Building over 50 years old (factor 0.8)	₹35,280	20%	₹7,056
Road wider than 12 m (factor 1.2)	₹52,920	20%	₹10,584
Lane up to 2.5 m (factor 0.6)	₹26,460	15%	₹3,969

Look at the last row. Once annual value drops below ₹30,000, the rate falls from 20% to 15%, so the bill drops by more than the factor alone suggests.

The transition cap

When the scheme began, KMC capped the change for existing assessments. The new tax could not exceed 120% of the tax under the last valuation, and could not fall below 80% of it. The form says the cap does not apply to first-time assessments, to assessee numbers created after the scheme was published, or where the use changed in the transition. A buyer of a new flat should therefore not expect the previous owner's capped figure to carry over.

Mutation: putting the flat in your name at KMC

Section 183 of the KMC Act, 1980 is the rule here, as quoted by the Calcutta High Court in Md. Shahid Amin v. Kolkata Municipal Corporation (12 March 2018). When title to land or a building is transferred, the transferor and the transferee must give written notice to the Municipal Commissioner within three months of the registration of the deed. Where title passes on death, the heir has six months. On receiving the notice and the fee set by regulation, the Commissioner records the change in the Municipal Assessment Book.

Two points matter for a buyer:

• Arrears follow the property. The Act lets KMC refuse mutation while dues remain unpaid, including the previous owner's. Ask the seller for KMC's no-dues position before you pay the balance.
• The seller stays liable until notice is given, but that does not reduce your own liability for the tax.

The Kolkata Municipal Corporation (Amendment) Act, 2022 adds section 183(8). It lets the Commissioner record a transfer on his own initiative, subject to the processing fee and arrears. Its sections take effect on dates the State notifies, and we could not confirm that this one has been notified. Do not rely on it; file the mutation yourself.

A mutation entry is a municipal tax record. It is your registered deed, not the KMC record, that makes you the owner. For a disputed inheritance or a large arrear, speak to a lawyer before you sign.