What a second income actually adds to a home loan

Eligibility is driven by income, so adding an income raises it. That is the whole mechanism, and it is close to linear.

What the numbers do

At 8.5% over 20 years, with lenders allowing instalments to take 45% of combined income:

Applicants	Combined income	EMI allowed	Loan supported
One	₹90,000	₹40,500	about ₹46,66,849
Two	₹1,50,000	₹67,500	about ₹77,78,082
Two, equal	₹1,80,000	₹81,000	about ₹93,33,698

Adding a ₹60,000 earner lifts the ceiling by ₹31,11,233. In many Indian cities that is the difference between two bedrooms and three, or between a long commute and a short one.

What it commits the co-applicant to

This is where the arithmetic stops being the point. A co-applicant is not a character reference. They are jointly and severally liable for the whole debt — not for a half of it.

In practice:

The lender can pursue either of you for the full amount. If one stops paying, the other owes everything, not their share.

It appears on both credit reports. A missed instalment damages both scores. So does the loan simply existing: it reduces what either of you can borrow separately afterwards, which matters if one of you later wants a car loan or a business loan.

Exiting is hard. Removing a co-applicant generally requires the lender's consent and often a refinance, which means fresh underwriting on whoever remains — and if they do not qualify alone, there is no exit. This is the clause people discover during a separation, which is the worst possible time.

Those are not reasons to avoid a joint loan. They are reasons to be deliberate about who the second name belongs to, and to know that "just helping with eligibility" is not what the document says.

Ownership and the tax question

Two things get conflated constantly: being a co-applicant on the loan and being a co-owner of the property. They are separate, and the combination determines who may claim what.

Broadly, in India, deductions on a home loan are available to someone who is both an owner of the property and a borrower on the loan, and each such person claims against their own share, within the limits applying to them. Someone on the loan but not on the title generally cannot claim; someone on the title but not the loan has nothing to claim against.

The detail — which sections apply, what the limits are, how a self-occupied property differs from a let one, and how your tax regime affects any of it — changes with the Finance Act and depends on your own circumstances. This is genuinely worth a conversation with a chartered accountant before the paperwork is drawn, because the ownership share is awkward to change afterwards and determines the tax position for the life of the loan.

Practical points that are easy to get wrong

Get the ownership share right at the start. It drives both the tax position and who owns what if things change. Fixing it later means a fresh transfer, with its own stamp duty.

The weaker credit score can set the rate. Lenders often price on the lower of the two, so a co-applicant with a poor score can raise the rate on the whole loan — occasionally enough to outweigh the extra eligibility. Check both scores before applying.

Both incomes have to survive the term. A ceiling built on two salaries assumes two salaries for twenty years. If one of you plans to stop working — to study, to raise a child, to start something — borrowing to the joint maximum is borrowing against an income that will not be there.

Decide on the instalment, not the ceiling

The eligibility figure is what a lender will permit, which is a different question from what you should take on. Put the instalment you would actually be comfortable with into the home loan calculator and look at the total interest, then compare it against the ceiling the two incomes unlock. The gap between those is a choice, not a constraint.