I would recommend you obtain and use an EIN on any tax reporting documents you may issue to vendors or clients. Especially since it's free and takes at most, 10 minutes to get on line.
I've been self-employed for will over 15 years now. Under no circumstances and with no exceptions will I give out my SSN. It's my business EIN or I take my business elsewhere.
If your SSN is compromised, that can ruin your entire life. Whereas if the EIN is abused, it only affects the business and is significantly easier to deal with the fallout should it actually be compromised and abused.
