What NACH actually is
NACH (National Automated Clearing House) is an RBI-regulated payment system that allows a lender to initiate a debit from your savings or current account on a schedule you authorize in advance — you don't need to transfer money manually each month. The mandate specifies the maximum debit amount, the frequency (monthly for EMIs), and the duration (the loan tenure).
The key word is "maximum" — many mandates are set up for a higher cap than your current EMI to accommodate future rate changes without requiring a new mandate. This means the lender has authorization to debit more than your current EMI if the mandate cap is set higher. Check the actual amount on the mandate you signed.
What happens when the debit fails
If your account has insufficient funds on the due date, the debit fails. You get a bounce charge from your bank (typically ₹300–₹1,000) and a separate charge from the lender (specified in your loan agreement). Many lenders automatically re-present the debit 2–3 times within the same month — and each failed re-presentation can trigger another round of charges.
The fastest way to stop re-presentation charges is to ensure the funds are in the account, even after the initial failure. Some banks process re-presentations within 24–48 hours; transferring funds immediately after a bounce notification can prevent subsequent failures.
Cancelling or modifying a NACH mandate
You can revoke a NACH mandate through your bank — but revoking the mandate does not cancel your loan obligation. The EMI is still due and must be paid through another channel (net banking, IMPS, or branch payment). Revoking a mandate without arranging an alternative is a common mistake that leads to unintentional missed EMIs — not because you didn't want to pay, but because the automatic debit no longer works and you forgot to pay manually.
If you're switching banks, set up the new mandate before cancelling the old one. There's typically a processing lag on new mandates — your lender needs to submit it to NACH and get it activated, which can take a few days.
PDCs (Post-Dated Cheques) and why they're different
Some older loan structures use PDCs instead of NACH — you give the lender a stack of post-dated cheques at the start of the loan, one per EMI month. A bounced PDC is treated differently from a failed NACH debit: it carries potential criminal liability under Section 138 of the Negotiable Instruments Act, which allows the lender to file a criminal complaint. Lenders rarely pursue this for a single bounce from an otherwise cooperative borrower, but the legal exposure exists.
If you have PDCs outstanding with a lender, keep track of which months are covered and ensure the account is funded ahead of those dates — you generally can't recall a PDC once it's been handed over.