W-9
https://www.irs.gov/pub/irs-pdf/fw9.pdf
I-9
1099
https://www.irs.gov/pub/irs-pdf/f1099msc.pdf
SS-4
https://www.irs.gov/pub/irs-pdf/fss4.pdf
1040-ES Estimated Tax for Individuals
https://www.irs.gov/pub/irs-pdf/f1040es.pdf
Form 1-ES Mass ES Estimated Tax for Individuals
https://www.mass.gov/files/documents/2019/06/19/dor-2019-estimated-form-1-es.pdf
Link To IRS Website