REGIME CHANGE ITR3 OR 4 FOR AY 25 - 26

FALSE. Once you've opted out of the new regime by filing Form 10IEA and filed ITR-3 in the old regime, you cannot opt-in to the new regime in the same financial year. However, you can opt-in to the new regime in the subsequent financial year by filing Form 10IEA again. As per the Income-tax Act, 1961, once a taxpayer has opted out of the new regime, they can re-enter the new regime only after a period of two years. So, if you've already opted out and filed ITR-3 in the old regime, you'll need to continue filing in the old regime for the next two years before you can opt-in to the new regime again.

FROM IT SITE

13.Form 10-IEA is applicable on me and now I want to withdraw the option of old tax regime in my ITR. What is the procedure for the same?

In case you opted old tax regime in earlier Assessment Year and you want to ‘re-enter’ the new tax regime, then you need to file Form 10-IEA for withdrawal of option in the form for the upcoming assessment year.

https://www.incometax.gov.in/iec/foportal/help/statutory-forms/file-statutory-form/popular-form/form-10-IEA-um