(From the IRS website:)
"Government entities are frequently asked to provide a tax-exempt number or “determination” letter to prove its status as a “tax-exempt” or charitable entity. For example, applications for grants from a private foundation or a charitable organization generally require this information as part of the application process. In addition, donors frequently ask for this information as substantiation that the donor’s contribution is tax deductible, and vendors ask for this to substantiate that the organization is exempt from sales or excise taxes. (Exemption from sales taxes is made under state law rather than Federal law.)
The Internal Revenue Service does not provide a tax-exempt number. A government entity may use its Federal TIN (taxpayer identification number), also referred to as an EIN (Employer Identification Number), for identification purposes.
Governmental units, such as states and their political subdivisions, are not generally subject to federal income tax. Political subdivisions of a state are entities with one or more of the sovereign powers of the state such as the power to tax. Typically they include counties or municipalities and their agencies or departments. Charitable contributions to governmental units are tax-deductible under section 170(c)(1) of the Internal Revenue Code if made for a public purpose.
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As a special service to government entities, IRS will issue a “governmental information letter” free of charge. This letter describes government entity exemption from Federal income tax and cites applicable Internal Revenue Code sections pertaining to deductible contributions and income exclusion. Most organizations and individuals will accept the governmental information letter as the substantiation they need."
View I.R.S. letter
