I'm new to taxes. A while back my employer had me fill out a document, and if memory serves, I incorrectly listed myself as Head of Household. How can I amend this?

You will have to fill out a new Form W-4 for your employer to correct that you are not Head of House Hold.  For your tax return file using the filing status that is correct for your situation, this will ensure that your taxes are correctly calculated.

Thank you.

You are welcome

It was probably a W-4. Ask your employer for another one. 

Thank you.