Schedule C:
Line D
Enter on line D the employer identification number (EIN) that was issued to you on Form SS-4. Do not enter your SSN on this line. Do not enter another taxpayer's EIN (for example, from any Forms 1099-MISC that you received). If you do not have an EIN, leave line D blank.
You need an EIN only if you have a qualified retirement plan or are required to file employment, excise, alcohol, tobacco, or firearms returns, or are a payer of gambling winnings. If you need an EIN, see the Instructions for Form SS-4.
See https://www.irs.gov/instructions/i1040sc#idm140229423597072
