The first step is get your credit report from credit rating agency - CIBIL.
The next step is to read it carefully and know the reason why your name is in the default list?
1- It could be due to Human Error e.g. Wrong - Name, DOB, Gender, PAN, Passport Number, Address etc.
2- It could be due to Incorrect Reporting/Mistake e.g. Wrong Credit Cards Details, Ownership - Accounts that aren't yours, but in your credit file, Late Payments - Reports of late payments in your credit file, when you paid on time or you may be a victim of identity theft.
3- It could be due to Loan Default e.g. Loan Defaults, Credit Cards Default, Late Payments and any other factors that are negatively impacting your CIBIL score and history.
For first reason, you would just need to report it to CIBIL with valid proof and they will fix it.
The second reason is also easy to fix. In these cases check out - who put you on default list e.g. Bank Name. If you have any acknowledge letter or any proof (related to above problem) from the bank or financial institution just submit that to CIBIL. If you don't have, you have to follow up with that bank and got a letter and forward it to CIBIL. CIBIL then verify the proof with the bank and incorporate the update on your credit file. With in few days the correct info will be displayed in your credit report.
If bank is not cooperating with you then write a letter to bank to fix it with a copy to CIBIL. If you don't hear from them in 30 days or not satisfied with the action you can lodge a complaint with Banking Ombudsman to resolve the issue.
The third reason could be that you have indeed defaulted on a loan and hence your name was entered in the defaulter list. If this is the case, You need to take up this with the defaulted bank and settle it out. And submit that settlement letter to CIBIL. The default will remain on your file but show as settled.
If you don't want to settle it than it will remain on your file for seven years and it will destroy your score. During this period no one will give you any loan or credit. After this seven year period, you again need to start rebuilding your credit by paying your loan and credit card bills on time.
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