Initial Tax Year

What’s the first year that the IRS expects a return for a c-corp? Is it the year the EIN is granted or the year the corporation actually engages in business? Is a return required in the formative year(s) (e. g. the owners/officers are drafting the agreements, filing articles of incorporation, opening bank accounts, securing financing/investments, but have not opened the doors for business)? For example, if the set up work was done in late 2005 and the corp opened for business in 2006, is a return due for 2005?

year EIN is granted. just put in zeroes and send it in. they expect something, even if it’s zeroes, and get antsy when they receive nothing.