The cost of my homes upkeep is split evenly between myself and my partner. How do I answer the question of whether or not I paid more than half the cost of home upkeep?

[fpsoftballqt02]

We are filing separately as we're not married. Home upkeep costs are split evenly. No one pays more or less than half.

[Bsch4477]

I assume that you are asking about filing as head of household and each has a qualifying child. 

IRS Memorandum SCA 1998-041

Memorandum SCA 1998-041 concludes that a household is not determined by physical boundaries, but by underlying facts. Two adults can share the same house and, if they otherwise qualify, each is a head of household as the IRS defines it. Certain expenses may be equally shared. These include "property taxes, mortgage interest, rent, utilities, property insurance and food." But other household expenses are normally paid by the head of each family, independent of the other. These include "clothing, education, medical treatment, vacations, life insurance and transportation." When these individual expenses are added to each household's shared expenses, each head of household has paid more than 50 percent of that household's expenses, and therefore both would qualify.

[ThomasM125]

The issue of who provides more of the cost of the home upkeep usually involves qualifying for head of a household filing status, which is important if you support dependents. Since you split the costs, if one of you is claiming children or others on your tax return, it would be more advantageous for that individual to have provided more support. It is doubtful that one of you didn't spend at least one dollar more in home expenses than the other, so the one who has children would probably qualify if you ran the numbers. If neither of you have dependents, then it may not matter if either one of you indicated that you provide greater support. However, you could run the tax returns both ways to see which is more advantageous, and then do some calculating to see if you can make the numbers add up.

[Opus 17]

When two people live together unmarried, the person who paid more than half the household expenses can also file as head of household if they claim a qualifying child dependent.  It only has to be $1 more than half, but if you each paid exactly half, then no one can claim HOH because no one claimed more than half.  

The IRS is unlikely to audit you unless there are other red flags so make your best guess.  It will usually be the person whose income is the higher, but that may not always be true if that person used their money for things that were not household expenses (like savings, or paying child support to another former partner). 

Also note that if you are living together unmarried, the parent who is claiming the child as a dependent should answer "no" to any questions about custody agreements, as that only applies to legal agreements between parents who are divorced or separated and live apart.  And the parent who is not claiming the child should not list the child at all, to avoid potential confusion.