The investigation wing of the income tax (I-T) department is going through the ‘residential’ status of non-resident Indians (NRIs) with a fine-tooth comb. Several NRIs have received notices from the department for reopening tax assessments of the past five to six years and were also told to share photocopies of their passports. A resident can attain NRI status by staying overseas for more than 182 days. The law also states that a person is a ‘resident’ if he has been in India for more than 60 days in the year in question and 365 days during the four years prior to that year.