The We The People Foundation had great packages for workers and employers both. The forms and instructions are free and available here. I highly endorse the We The People Foundation and suggest you get all your forms from them. However, I did do a lot of research myself before discovering the Foundation, and the forms that I made are 100% legal and usable, they just have less field proving.
26 USC § 1 imposes the income tax on “taxable income.”
26 USC § 63 defines “taxable income” generally as “gross income” minus deductions.
26 USC § 61 defines “gross income” generally as income “from whatever source derived.”
26 USC § 861 – 865, and related regulations, determine the taxable “sources of income.”
26 CFR § 1.861-8 shows that the taxable “sources of income” apply only to those engaged in international or foreign commerce.
Here are some forms to give to your employer in lieu of Form W-4:
Withholding Exemption Certificates and Statements of Citizenship
A “withholding exemption certificate” is a form individuals may voluntarily use to certify to the employer that the individual is not liable for U.S. income tax and exempts the employer from any U.S. income tax withholding rules.
An individual’s written statement that he or she is an American Citizen may be relied upon by the payer of the income as proof that such individual is a citizen or resident of the united States of America and therefore not subject to the U.S. income tax.
wec-coc.pdf – Withholding Exemption Certificate / Statement of Citizenship combo.
Transmittal letters are what the employer sends to the Internal Revenue Center stating that they requested a SSN as instructed by section 26 USC § 6109(a)(3) and 26 CFR § 301.6109-1(c) and that they are, according to 26 USC § 6724(a) and 26 CFR § 301.6724-1(a), are requesting a waiver of penalties that may be associated with the justifiable failure that is due to reasonable cause: 1) To withhold tax from payments, and 2) To use a Social Security Number in making reports to the I.R.S..