You can link up to 3 bank accounts to the trading account. One bank account will be the primary bank account, and the others will be marked as secondary bank accounts.
If you want to change your primary bank account, check this out – How do I change the primary bank details linked to my Trading account?
You can add a secondary bank account to your Fyers Trading account by submitting Secondary Bank Account Addition form. Please fill out the form, sign and scan filled form along with below-mentioned proof and mail us at email@example.com; you will receive a unique ticket number to your Email address, which you can use to track the progress and responses online.
Bank proof can be accepted are –
Scanned Copy of cancelled Cheque
Latest 1 Month Bank statement (Self Attested)
Latest Passbook Statement (Self Attested)
Please Note: The bank statement must contain Your Name, Account Number, IFSC and MICR code.