I have not changed my name, but just never used my full name in my everyday life. However, due to a new job that is strict on identity, I have to start using my full name which includes 2 last names. I am now confused on how I was able to file with just one last name before, and am wondering if I'll be able to file with two last names next year without having to do anything extra.
Again, my two last names ARE on my social security card.
The IRS matches its records with the Social Security Administration. On your tax return you should use your name and SSN exactly as they appear on your current Social Security card.