Section 43B(h): The 45-Day MSME Payment Rule Explained

What the rule says

Section 43B(h), introduced by the Finance Act 2023 and effective from 1 April 2024, ties a tax deduction to prompt payment. In plain terms: an amount you owe a micro or small enterprise for goods or services is deductible only if you pay it within the timeline set by Section 15 of the MSMED Act. Miss the timeline, and the expense is disallowed in the year it was incurred, and becomes deductible only in the year you actually pay.

The intent is to protect small suppliers' cash flow by making late payment expensive for the buyer, not through a fine, but by deferring the buyer's tax deduction. It changed MSME payment from a commercial preference into a tax compliance question.

The 15 and 45-day timelines

The deadline depends on whether you have a written agreement with the supplier:

The crucial point is the 45-day ceiling. A written agreement lets you extend beyond 15 days, but only up to 45. If your agreement specifies 60 or 90 days, that clause is valid commercially but not for tax, the excess beyond 45 days does not protect you. For tax purposes, 45 days is an absolute cap.

Who it applies to

The rule is narrower than many assume, which matters both ways:

• Only Micro and Small enterprises are covered. Payments to Medium enterprises are outside Section 43B(h).
• Only manufacturers and service providers. Purchases from suppliers registered as traders under the MSMED Act are excluded, the rule targets those who make or provide, not resellers.
• The supplier must be MSME-registered (Udyam) at the time of the transaction for the rule to bite.

So the practical task is to identify which of your suppliers are registered Micro or Small manufacturers or service providers, and treat their invoices under the clock. Getting your supplier classification right is where our MSME compliance service and vendor management service earn their keep.

What disallowance actually means

Disallowance does not mean you lose the deduction forever, it means you lose it this year. The unpaid amount is added back to your taxable income for the year in which the expense was incurred, and you can claim the deduction only in the later year when you actually pay.

The cash-flow sting is immediate. If ₹50 lakh of purchases from a small enterprise sits unpaid on 31 March, that ₹50 lakh is added to your income, and at a 30% effective rate you pay roughly ₹15 lakh of extra tax now, recovering the deduction only when you eventually pay the supplier. You are, in effect, taxed on money you still owe.

Two further consequences: late payment attracts compound interest at three times the RBI bank rate under the MSMED Act, and that interest is itself not deductible. And your tax auditor must report unpaid MSME dues in Form 3CD, so the disallowance is visible and gets added back, by you or by the CPC when it processes your return.

Two worked examples

The 60-day agreement trap. Amit buys fabric worth ₹80 lakh in January 2026 from three MSME-registered weaving units, with written agreements specifying 60-day credit. He assumes the 60 days protects him and pays on day 58. But the 45-day cap overrides the agreement, so all ₹80 lakh is disallowed for the year, adding roughly ₹24 lakh to his tax bill now. He recovers it next year, but the working-capital hit is immediate. The lesson: agreements beyond 45 days give no tax protection.

The no-agreement 15-day sting. A buyer takes ₹15 lakh of services from a small enterprise with no written agreement. Payment was therefore due within 15 days of acceptance. He pays 35 days after that deadline, so the ₹15 lakh is disallowed this year and shifts to next year. The lesson: without a written agreement the window is just 15 days, which is brutally short, so any ongoing MSME engagement should have a written agreement specifying a credit period up to 45 days.

How to stay compliant

Staying clear of Section 43B(h) is a process, not a one-off. The essentials:

• Identify your MSME suppliers. Ask vendors for their Udyam registration and classification (Micro, Small or Medium) and flag Micro and Small manufacturers and service providers.
• Put written agreements in place specifying a credit period up to 45 days, so you get the longer window rather than the 15-day default.
• Track invoices against the clock, especially those approaching 31 March, and prioritise MSME payments at year-end.
• Reconcile before the year closes. Review all payables to Micro and Small vendors before 31 March; anything unpaid past its deadline will be disallowed.
• Keep the classification current, since a supplier's MSME status can change.

This is exactly the kind of recurring discipline that is cheap to run and expensive to ignore. Our MSME compliance and receivable management services build this tracking into your payment process so year-end holds no surprises.

Quick answers

What is the deadline to pay an MSME? 15 days without a written agreement, or the agreed period up to a maximum of 45 days with one. Who is covered? Registered Micro and Small manufacturers and service providers, not Medium enterprises and not traders. What happens if I pay late? The expense is disallowed this year and deductible only in the year you pay, plus non-deductible interest at three times the RBI rate. Does a 60-day agreement help? No, the cap is 45 days regardless. If MSME payment tracking is not built into your process, our MSME compliance service sets it up.