Investment-proof season: Form 124 replaces Form 12BB and now asks your landlord's Aadhaar and your relationship with them

October is when payroll teams start chasing investment proofs, and for the tax year that began on 1 April 2026 the paperwork has a new name. The Income-tax Rules, 2026, notified as G.S.R. 198(E) on 20 March 2026, retire the familiar Form 12BB and replace it with Form No. 124 under Rule 205. The new form does more than renumber the old one: for house rent allowance it now asks for your landlord's Aadhaar number and your relationship with the landlord, if any. This piece walks through what Rule 205 requires, how the disclosure works on a real rent figure, and the mistakes that will draw questions from your employer's payroll desk.

Quick reference: Form 124 is filed with your employer, not with the Income Tax Department. It feeds the employer's estimate of your salary income for computing TDS under section 392(5)(b) of the Income-tax Act, 2025.

What the Section Says

Rule 205 of the Income-tax Rules, 2026 (effective 1 April 2026) says that an employee shall furnish to the employer, described in the rule as the person responsible for paying salary under section 392(1) of the Income-tax Act, 2025, the evidence or particulars of claims in Form No. 124. The employer uses those particulars to estimate your income and compute TDS on salary under section 392(5)(b). In practical terms, Form 124 is the successor of Form 12BB, which did the same job under the Income-tax Rules, 1962.

The table in Rule 205(2) lists four kinds of claim and the evidence each one needs:

How Form 124 is laid out

The form itself has two parts. Part A, the identity block, carries five items plus the year: employee name, address, PAN, email, contact number and the tax year. Part B carries the four claim blocks in the same order as the table above.

Three changes stand out against Form 12BB. First, the HRA block now has a field for the landlord's Aadhaar number. Second, it has a field for your relationship with the landlord, which matters most when the rent is paid to a parent, spouse or other relative. Third, the deductions block uses the section numbers of the 2025 Act (123, 124, 130, 131 and so on), not the old 80-series numbers. The briefing for this piece is explicit that the new numbers should not be mapped to old sections beyond what the Rules themselves verify, so read each heading in the form as it is printed and ask your payroll team if a label is unclear.

Rule 205 also sits next to Rule 208, which prescribes Form No. 125 for specified senior citizens dealing with a bank; that form is covered in the FAQ below.

Worked Example

Take Meera, a salaried employee in Pune, whose basic salary is Rs 6,00,000 for tax year 2026-27 and who receives HRA of Rs 2,40,000 (Rs 20,000 a month). She pays rent of Rs 18,000 a month, or Rs 2,16,000 in the year, to her uncle, who owns the flat.

Step 1: Does the landlord-PAN line apply? Her aggregate rent is Rs 2,16,000, which is above the Rs 1,00,000 threshold in Rule 205(2) and Note 3 of Form 124. She must give her uncle's name, address and PAN. The form also has fields for his Aadhaar number and for her relationship with him, which she fills in as "uncle".

Step 2: What would the HRA exemption be? Under section 10(13A) of the Income-tax Act, 1961, the exempt HRA was the least of three figures: actual HRA received; rent paid minus 10% of basic; and 50% of basic in a metro or 40% of basic in a non-metro. The 2025 Act renumbers the provisions, so check the current section with your employer, but the arithmetic below shows why the disclosure matters. Pune is treated here as a non-metro for the 40% limb.

So Rs 1,56,000 of her Rs 2,40,000 HRA would be exempt and Rs 84,000 would remain taxable. You can run your own figures through the HRA exemption calculator and generate monthly receipts with the rent receipt generator.

Step 3: What changes with Form 124? Under Form 12BB, Meera would have disclosed her uncle's PAN because the rent crossed Rs 1 lakh. Under Form 124 she also records that the landlord is a relative and gives his Aadhaar number. That makes the claim easier to check: the uncle should be showing Rs 2,16,000 as rental income in his own return. If he does not, the mismatch is visible from the data Meera has already given her employer.

Step 4: A second landlord. If Meera had moved in October and paid Rs 15,000 a month for six months to one landlord and Rs 18,000 a month for six months to another, her aggregate rent would be Rs 90,000 + Rs 1,08,000 = Rs 1,98,000. The threshold in Rule 205(2) is on aggregate rent in the tax year, so both landlords' details are needed, and the HRA block in Part B is repeatable for exactly this case.

Common Mistakes

1. Treating the Rs 1 lakh test as per landlord. Rule 205(2) refers to aggregate rent paid in the tax year. In the two-landlord case above, neither landlord individually received more than Rs 1,08,000, but the total of Rs 1,98,000 is what counts.

2. Leaving the relationship field blank. Form 124 asks for the relationship with the landlord "if any". Paying rent to a parent is a common arrangement, and the form now asks you to say so. A blank field where a relative is the landlord is exactly the kind of gap a payroll reviewer or a later scrutiny notice will query.

3. Submitting without Annexure A-1. Note 4 lists the house rent agreement as annexure A-1. Rent receipts alone may not satisfy an employer that follows the form strictly. Keep a signed agreement covering the full period from 1 April 2026.

4. Using old section numbers. The deductions block lists sections 123, 124, 130, 131 and others under the 2025 Act. Writing "80C" on a 2026-27 declaration may confuse payroll software built around the new numbering. Use the headings exactly as they appear in the form; our Section 80C glossary entry explains the old provision for context only.

5. Assuming every claim works in either regime. Form 124 records claims; it does not decide whether a deduction is available to you. The briefing for this piece makes no claim about which deductions are allowed in the new regime, and nor should you without checking. Compare both regimes in the old vs new regime calculator before you submit.

6. Missing the lender's PAN on a home loan. Block (3) asks for the name, address and PAN of the lender, whether a financial institution, your employer or another person. Annexure A-3 is the loan agreement. A bank's interest certificate without the agreement may leave the claim incomplete.

7. Forgetting that Form 124 is not your return. What you declare to the employer drives TDS during the year; the final position is settled in your return. If you missed a claim in Form 124, it can still be made when you file, but the employer's Form 16 will not show it. Use the TDS calculator to see how a missed declaration changes monthly deductions.

FAQ

What is Form 124?

Form No. 124 is the statement of evidence or particulars of claims that an employee gives the employer under Rule 205 of the Income-tax Rules, 2026, for computing TDS on salary under section 392(5)(b) of the Income-tax Act, 2025. It replaces Form 12BB from 1 April 2026.

Do I need my landlord's PAN if my rent is Rs 8,000 a month?

At Rs 8,000 a month, aggregate rent is Rs 96,000 in the year, which is below the Rs 1,00,000 threshold in Note 3 of Form 124. The landlord-PAN requirement is tied to aggregate rent exceeding Rs 1 lakh.

Why does Form 124 ask for my relationship with the landlord?

Rule 205(2) asks for the relationship with the landlord, if any, alongside the landlord's name, address and PAN. The field records arrangements such as paying rent to a parent or relative, which the earlier Form 12BB did not ask about.

What documents do I attach to Form 124?

Note 4 lists four annexures: A-1 house rent agreement, A-2 LTC documents, A-3 loan agreement, and A-4 documents for Chapter VIII deductions. Attach those that match the claims you make in Part B.

I have two landlords this year. How do I fill the HRA block?

The HRA block in Part B is repeatable for multiple landlords. Give the name, address, PAN, Aadhaar number, relationship and rent paid for each one. The Rs 1,00,000 test applies to the aggregate rent across all landlords in the tax year.

Is Form 124 the same as Form 125?

No. Form No. 125, under Rule 208, is the declaration a specified senior citizen gives to the specified bank under section 393(1) [Table Sl. 8(iii)], and includes the PPO number and whether the person opts out of the new regime under section 202. Form 124 is for employees and goes to the employer.

What if I do not submit Form 124 by my employer's deadline?

The employer will compute TDS on the particulars it has, so tax deducted may be higher than your final liability. Claims not made through Form 124 can still be made in your return; the source document for the Rules is on incometax.gov.in.

Sources: Income-tax Rules, 2026, G.S.R. 198(E) dated 20 March 2026, Rules 205 and 208 and Forms 124 and 125, published on the Income Tax Department portal. For the full text of the Income-tax Act, 2025 see India Code and the e-filing portal. See also our HRA glossary entry.