what is a 501c3 letter
Contents. The most important part of the determination letter is the statement by the IRS that the organization qualifies for tax-exempt status under section 501(c)(3) of the Internal Revenue Code.se. An organization will normally use its determination letter as proof that it is an IRS-recognized nonprofit. For instance, when raising funds by soliciting contributions or applying for grants, the charity may be asked to prove its 501c3 status.