Form 124 (Old Form 12BB): How to Fill It, With a Sample

If your employer has asked for 'Form 124' this year and you have never heard of it, you have. It is the investment and rent declaration that used to be called Form 12BB, renumbered when the Income-tax Rules, 2026 came in with the new Income-tax Act from 1 April 2026. The form now prints the new section numbers, which is where most people get stuck. This page goes through it part by part, with a filled sample, the proof each part needs, and the slips that turn into a big TDS cut in January to March.

What changed, and what did not

What it covers did not change. Rule 205 still lists four kinds of claim: house rent allowance, leave travel concession, interest on a house-property loan, and Chapter VIII deductions. What changed is the numbering of the sections those claims sit under.

Source: Income Tax Department: Form No. 124 FAQ (earlier Form No. 12BB; rule 26C to rule 205; section 192 to 392(5)(b))

Source: Income-tax Rules, 2026, rule 205: the four claims and the evidence for each

Who gives it, to whom, and how

• You, the employee, give it to your employer, the person responsible for deducting tax from your salary. It is used to estimate your income and work out your TDS.
• It is optional. You file it only if you want the employer to count your claims. If you do not, the Department's FAQ says the employer deducts TDS without allowing any deduction or exemption.
• You can hand it over on paper or electronically. It is not uploaded on the income-tax portal.
• The standard deduction needs no declaration; it is allowed in every case.
• Changed jobs during the year? The FAQ says to also give the new employer your income and TDS from the previous one, in Form No. 122.

The rules set no date for it. In practice most employers collect a declaration at the start of the year and the proofs in January or February, so the last three months' TDS can be corrected.

Part A: your details

Part A asks for your name (first, middle and last, in full, with no abbreviations, says Note 1), your address, your PAN, email, contact number with country code, and the tax year. Note 2 lists what the address must contain: country, flat or door number, road or street, PIN, post office, area, district and state.

Part B: a filled sample

The sample below follows the rows of Form No. 124 as published by the Department. Every name, number and amount is made up: Ramesh Kumar Sharma, PAN ABCDE1234F (sample), tax year 2026-27, old regime.

The section numbers in row 4 are the new ones, and they are the ones the form itself prints. In plain terms: section 123 is the old 80C (life insurance, provident fund, tuition fees and the rest, listed in Schedule XV), section 124 is the old 80CCD (pension scheme contributions), section 126 is the old 80D (health insurance), and section 129 is the old 80E (education-loan interest). The form names sections 129, 133, 137 and 153 as examples of 'other sections'.

Source: Form No. 124 (Part A, Part B rows 1-5, declaration, Notes 1-5), Income Tax Department

The limits behind the sample

Source: Income-tax Act, 2025, section 123 (deduction capped at Rs. 150000), Income Tax Department

Source: Income-tax Act, 2025, Schedule XV (items that qualify under section 123)

Source: Income-tax Act, 2025, section 124 (pension scheme contributions)

Source: Income-tax Act, 2025, section 126 (health insurance premia)

Source: Income-tax Act, 2025, section 22 (interest on borrowed capital, lender's certificate)

The proof that goes with each part

• HRA: the landlord's name, address and PAN (when the year's rent exceeds the limit) and your relationship with the landlord, says rule 205. The form adds the rent agreement as Annexure A-1. Rent receipts are what most employers ask for on top.
• LTC: 'evidence of expenditure', meaning tickets and payment proof, attached as Annexure A-2.
• Home-loan interest: the lender's name, address and PAN under rule 205, the loan agreement as Annexure A-3, and the lender's interest certificate that section 22(2) needs for the higher cap.
• Chapter VIII: 'evidence of investment or expenditure' under rule 205, attached as Annexure A-4: premium receipts, fee receipts, contribution statements.

If you are in the new regime

The new regime under section 202 is the default. Section 202(2) computes income without the HRA exemption (Schedule III serial 11), without LTC (serial 8), without interest on a self-occupied home under section 22(1)(b), and without Chapter VIII deductions other than sections 124(1) and 124(2), 125(2) and 146. Section 124(1) is the employer's contribution to your pension account, which your employer already knows. So in the new regime there is usually little or nothing for Form No. 124 to carry. Tell payroll which regime you want TDS worked on before you fill anything.

Source: Income-tax Act, 2025, section 202(2): what the new regime does not allow

Slips that bring a big TDS cut in January to March

• Not submitting the form or the proofs at all. The employer then deducts TDS with no deduction or exemption, and the whole year's catch-up falls on the last few salaries.
• Leaving out the landlord's PAN when the year's rent crosses the limit. Payroll can then drop the HRA claim.
• Counting the same NPS deposit under section 123 and section 124(3). The law allows it under one only.
• Declaring more home-loan interest on a self-occupied house than the section 22(2) cap.
• Declaring parents' health insurance above the section 126 limit, or paying the premium in cash.
• Switching jobs and not giving the new employer Form No. 122 with the earlier salary and TDS.
• Declaring in April and never sending proofs. A declaration is an estimate; the proof is what keeps the claim.