You have it backwards. If you are a contractor, the individual or business that you will perform work for will issue a 1099NEC to you. They will likely ask you to fill out a W-9 that gives them your Social Security number or Tax ID so that they can pay you and report the amount they pay you to the IRS/
If you are an independent contractor, they do not withhold Social Security, Medicare or tax from your pay, so at tax time you pay it all yourself. You enter the 1099 they issued to you on your tax return. You may need to pay quarterly estimated tax payments to avoid a big tax bill or a penalty at tax time.
https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/00/25922
https://ttlc.intuit.com/questions/2902389-why-am-i-paying-self-employment-tax
https://ttlc.intuit.com/questions/1901340-where-do-i-enter-schedule-c
https://ttlc.intuit.com/questions/3398950-what-self-employed-expenses-can-i-deduct
https://ttlc.intuit.com/questions/1901110-do-i-need-to-make-estimated-tax-payments-to-the-irs
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
