In order to file taxes as head of household, there are certain criteria an individual must meet. The process of determining whether or not you are qualified for this filing status is referred to as "head of household due diligence." 

Effective with 2018 tax returns, a paid preparer is subject to due diligence requirements in determining a client’s eligibility for the head of household filing status. (IRC Sec 695(g), as amended by Sec 11001(b) of the TCJA) For returns filed in 2025, the penalty for failing to exercise due diligence with respect to the head of household status is $635. Form 8867, Paid Preparer’s Due Diligence Checklist, includes a section for this head of household requirement.