By IndiaHub 
To file Form 10-IEA on the Income Tax portal, log in with your PAN and password, then go to e-file > Income Tax Forms > File Income Tax Forms. Search for Form 10-IEA, select your assessment year, and begin the filing process after reviewing the list of required documents.
If you have income from a business or profession, select the relevant due date and proceed. When prompted, confirm your choice to shift from the new tax regime to the old regime.
The form will auto-fill your basic details such as name and PAN. Based on your previous year’s filing, the regime option will be pre-selected. For first-time opt-outs, the “opt-out” choice will appear by default; for repeat filings, the system will pre-select re-entry. Save the details once reviewed.
If applicable, provide IFSC unit details; otherwise, this section will remain inactive for opt-outs. Finally, review the verification and declaration, agree to the terms, and preview all entries.
The form must then be verified using Aadhaar OTP, DSC, or EVC before final submission. Once submitted, you’ll receive an acknowledgement with a transaction ID and an acknowledgement number.