EIN - Employer Identification Number. This number is issued by the IRS to a business, not an individual.
TIN - Taxpayer Identification Number. Sometimes referred to as ITIN (Individual Taxpayer Identification Number), this number is issued by the IRS to a living, breathing person who for whatever reason, does not qualify for a social security number.
When self-employed and asked to fill out a W-9 (W-10 for some) under no circumstances and with no exceptions what-so-ever should you provide your SSN or TIN. Always provide your EIN. That way, if your EIN is abused it only affects your business. WHereas if your TIN or SSN is abused it has a very high potential of ruining your entire life forever.
If self-employed and you do not yet have an EIN, you can get one for free for your business and it only takes about 10 minutes. Just go to https://www.irs.gov/businesses/small-businesses-self-employed/apply-for-an-employer-identification-n... and read and follow the instructions.
