Businesses are required to file 1099s to their vendors if they pay more than $600 per year.
Landlords are generally not businesses, although this is somewhat confused and it is being debated.
The IRS has stated that even if you are not required to file a 1099, you may do so voluntarily, because it helps to increase tax compliance. If you don't have an EIN, you would use your SSN.
Finally, you don't need to issue a 1099 even if you are a business, if the person you are paying is an S- or C-corp. You only need to issue the 1099 to partnerships and sole proprietors. You find this out by giving the vendor a form W-9 to fill out to collect their tax number, and see which box they check on the form.
