Can a collections agency report me to the credit bureau without my
social security number?  They have my name, phone number, and previous
address.  My last name is also uncommon enough that my full name
uniquely identifies
me in the US.  Will this be enough information for them to damage my credit?

Also, can I force the agency to reveal whether or not they have my SSN?

Hello gquerymeister,

Yes, a collection agency can definitely report you to a credit bureau
without having your social security number. Even with a common last
name, with the information you listed above they could add a negative
report to your file, although it might make it easier for you to
challenge it.

The simple answer is if they were able to run a credit check on you
successfully with the information you gave them, they will be able to
successfully add a negative report to your credit. Also, if you gave
them permission to do a full credit check on you, they may have gotten
a copy of your credit report with your SSN right there on it
(depending on what credit bureau they used and what state you are in).

As to whether or not you can force them to reveal whether or not they
have your SSN, this could depend on a lot of different factors, but it
would be easier for you to find out just by verifying with the credit
bureau whether or not they added a bad report to your file. There
might be some disclosure laws that could force them to reveal this
information to you, although this is irrelevant because they do not
require your SSN to add a negative report.

I know from personal experience that not requiring a SSN can still
give you a bad report on your credit. A good friend of mine
approximately two years ago ran into a problem. With her, they only
had the current address and her name and it appeared on her credit
report and hurt her credit for a few months. This was a case of her
being sent something that she never ordered (from a popular mail order
company), and then her refusing to pay the bill. They did not have her
SSN but were able to add the negative comment to her credit history.
She did however successfully get it removed by disputing it, although
the process took a few months.

There are people who don't even have a SSN on their credit bureau
accounts (at all), items can get added from name/address/birth
information only. Here is an example:
http://www.docdroppers.org/wiki/index.php?title=Starting_a_credit_history_without_an_SSN

Here is a discussion from expertlaw.com that discusses a case where no
SSN was provided: http://72.14.203.104/search?q=cache:pwxDZQ6ddHcJ:www.expertlaw.com/forums/post-1998.html+credit+bureau+%22without+ssn%22&hl=en&ct=clnk&cd=9

I hope this provides you with the answer you were expecting. Please
let me know if you require any additional clarification and I will do
my best to further assist you.

All the best,

tisme-ga

Very helpful.  Thank you.