Is IRS recognition necessary before we receive donations?

Summary:

Strictly speaking, no. But many larger donors require evidence of 501(c)(3) status and it offers reassurance to all.

Sandra Pfau (spfau@COMPUTER.ORG) wrote to the ARNOVA-L list on March 4, 1998:
Proof of recognition of tax-exempt status is provided in the form of a
letter from the IRS. While it is recommended that most nonprofit
organizations apply to the IRS for recognition of exemption, it is not
absolutely required. Most private foundations require proof of
exemption by means of a copy of the IRS exemption letter. However,
the most notable exception to seeking recognition of exemption is for
mainstream religious demoninations.

With respect to receipts for donors, any form of receipt indicating
the amount contributed is sufficient. If noncash gifts are provided,
you may want to use IRS Form 8283 to acknowledge the gift. More
information from IRS publications and forms is available on my web
site at: http://www.nonprofitlaw.com. Look under "IRS Forms". These forms
and publications also are available from the IRS web site -- http://www.irs.gov.