Advance tax wrongly deposited as self assessment tax for previous year

A client mistakenly paid advance tax for the 2024-25 assessment year under the wrong assessment year and minor head code, specifically as self-assessment tax for the already assessed 2023-24 year. The advice given is to write to the Assessing Officer (AO) to request a challan correction. This process involves an application to the AO and may take time as the department verifies the mistake and whether the funds can be adjusted against other demands.