A long-term mortgage should never be a sign-and-forget exercise. Keep your eyes and ears open about the new rules and changes in interest rates. The RBI is planning to change the base rate formula, which could change the way your bank calibrates its lending rates. Keep shopping around for the best rate and switch to a cheaper loan if possible. However, the difference should be at least 2 percentage points, otherwise the prepayment penalty

on the old loan and processing charges of the new loan will eat into the gains from the switch.

Also, switching will be more beneficial if done early in the loan tenure. Suppose you have a loan at 11.75% and are being offered a new rate of 9.9%. You can save up to 52 EMIs if the loan still has 18 years to go. But if the loan only has five more years to go, the new loan tenure will be only three EMIs shorter.

The same applies to prepayment of loans.The earlier you do it, the bigger is the impact on the loan tenure. The RBI does not allow banks to levy a prepayment penalty on housing loans but they may levy a penalty on other loans. Some lenders do not charge a prepayment penalty if the amount paid does not exceed 25% of the outstanding amount at the beginning of the year.