The Capdale attorney link referenced by Nilodop speaks of revised administrative procedures for exempt orgs and warns that it may not be as easy as before.
Still, the IRS web guidance seems to encourage a retroactive application:
“In general, an organization must file its exemption application within 27 months from the end of the month in which it was formed. If it does so, it may be recognized as exempt back to the date of formation. If an organization files its exemption application after the 27-month deadline, exempt status may only be recognized from the filing date forward.
Exceptions to this general rule apply. If an organization answers yes to Line 2, Part VII, indicating that it filed late, it is directed to Schedule E, which asks questions to establish if it is excepted from the general rule."
https://www.irs.gov/charities-non-profi ... -formation From the current the current (April 2018) IRS website:
“An organization that files an application after the 27-month deadline may be recognized as tax-exempt from the date of the application. It may also request exemption effective back to the date of creation by completing Schedule E, Form 1023, and checking the Yes box in Question 5 of that schedule.
A request will be approved if the organization acted reasonably and in good faith, and granting relief will not prejudice the interests of the government. These standards are usually met if the organization files its application before the failure to file is discovered by the IRS.”
https://www.irs.gov/charities-non-profi ... filed-late From the 1023 application:
IRS 1023 application wrote:“Do you wish to request an extension of time to apply to be recognized as exempt from the date you were formed? If “Yes,” attach a statement explaining why you did not file this application within the 27-month period.”