Applying for a number: You apply for a Social Security Number by filing an SS-5 form with the Social Security Administration. SS-5 forms are posted on the Social Security Administration's Web site (www.ssa.gov/online/forms.html).
Finding Social Security Numbers: If you have a person's name, you may be able to look up his or her social security numbers using Accurint, Merlin, KnowX and/or LocatePlus. However, you may want to check with the company first, because the number may be masked for privacy purposes. Merlin is said to be more willing to provide complete social security numbers if a business can demonstrate a permissible use.
If the person might have died, search the Social Security Death Index, which lists people who were receiving Social Security when they passed away. The Index is posted free on RootsWeb.com. It is also available through Ancestry.com and Lexis (FINDER;DCEASE).
Other places to find social security numbers: court records, death records and professional licensing records.
Validating a Number: If you have a social security number, the SSN Validator will tell you whether that number was actually issued and, if it was, where and approximately when, and possibly whether there is a related death record (www.ssnvalidator.com/pages/search.aspx). You could also register and use the government's official validator (www.socialsecurity.gov/employer/ssnv.htm), or you could run the number through the databases discussed in the entry for "Finding People."