Having a PAN and not filing a return may be a strict NO NO. It can trigger assessment notice.
In a case of non resident [2024] 461 ITR 473 (Mad) under employment at Singapore he made a transaction of purchase of immovable property in India from out of his sources of income returned in Singapore. Since he has not filed any return in India he received a notice alleging escapement of income equal to the investment so made in purchase of property in India.
This lead to litigation which could have been avoided had he filed his return in India of the year in which he made such purchase.
It is thus advisable that everyone who holds a PAN should file return of income by the due date no matter that the income earned during the year is less than that chargeable to tax