How do I file a complaint with the RBI Ombudsman, and what must I do first?

The Ombudsman only takes complaints the bank has already had a fair chance to fix, so the order matters:

1. Complain to the bank in writing first. Email customer care or the grievance cell, and keep the reference number. Phone calls leave no record.
2. Escalate within the bank. If the reply is unsatisfactory, write to the Nodal Officer or Principal Nodal Officer (their emails are on the bank's grievance page).
3. Wait for the bank's final reply, or 30 days. You can file once the bank rejects you, gives a resolution you're not satisfied with, or doesn't resolve it within 30 days.
4. File on the RBI CMS portal (cms.rbi.org.in). Choose the regulated entity, describe the facts briefly, state the relief you want (including compensation, if any), and upload your evidence as a single PDF: the email chain, screenshots, and the bank's replies.

A few things that helped in my complaints:

• Formally decline an inadequate offer in writing. If the bank offers a token goodwill amount that doesn't address the problem, decline it by email before filing, so it can't later claim the matter was settled.
• Don't file late. File while the bank's last reply is recent; the scheme has time limits.
• Make sure it isn't already elsewhere. A complaint pending in a court or consumer commission can't also go to the Ombudsman.

I wrote about one full complaint, from dispute to compensation, here: compensation from Axis Bank after an RBI Ombudsman complaint.