How to activate inoperative savings bank account

If there have been no transactions in a savings or current account for more than two years, the account will be considered inactive or dormant. The accounts that have not been used for more than two years will be noted by banks and kept in different ledgers.

According to the RBI notification on unclaimed deposits and inoperative, "A savings as well as current account should be treated as inoperative / dormant if there are no transactions in the account for over a period of two years. For the purpose of classifying an account as 'inoperative' both the type of transactions i.e. debit as well as credit transactions induced at the instance of customers as well as third party should be considered."

According to the HDFC Bank, here is the process to activate dormant account for customers.
Step1: Visit the branch and submit written application with your signature a sper operating instructions in the account
Step2: Submit self-attested proof of identity and address
Step3: Initiate any transaction and your account will be activated once again

According to the IDFC FIRST Bank, here is the process to activate it:
You must submit a written application to the bank. For joint accounts, signatures of all accountholders will be needed, irrespective of a single or joint operating mode.
You will have to submit your KYC (Know Your Customer) documents. These will include address proof, PAN Card, and identity documents.
You have to do at least one financial transaction.

Banks turn accounts that have been inactive for a while into dormant accounts in order to decrease fraud. When an account has been designated as dormant, you cannot log in, make payments, transfer money, make withdrawals, or even log out.
According to the IDFC First Bank, "When an account is flagged as "Dormant", all customer induced debit and credit transactions will be blocked. Transactions included will be both financial (cash deposit/withdrawal, Fund transfer, IMPS, RTGS, NEFT, or any transactional mode such as UPI) as well as non-financial (cheque book requests, debit card request)."

Whether the account is active or not, interest on savings bank accounts will be credited on a regular basis. The amount left unclaimed with the bank after a Fixed Deposit Receipt matures and the proceeds are not paid will earn interest at the savings bank rate, as per the RBI.

According to RBI guidelines, no charges are to be levied by the bank to make the inoperative account active.