There are two key facts for HOH.
1. When considered over the whole year, did the taxpayer pay more than half the cost of maintaining their household? Since you split in April, this is probably true, but we can imagine an extreme case, where for 4 months, you lived in a mansion with a cost of living of $100,000 per month and your spouse paid all, and for 8 months you lived in a $1000 per month studio apartment. Your overall cost for the year is $208,000 (half the joint cost and all the separate cost) but you did not pay more than half. You may want to write down an estimate of your housing costs from Jan-April and from May-December, and how much you paid, to keep in case of audit.
2. Did you provide care in your home for a qualifying dependent. Here, the key is that children need to live in your home more than half the nights of the year. That's 183 or more nights. If you split in April, then each parent can claim about 100-120 nights, when you all lived together. But after that, where did the children live? Did each parent have overnight custody for at least 83 more nights (183 in total). If the children lived only with parent A, then parent B does not qualify to claim the children as dependents or use them for HOH. Even if parent A signs a release form for some of the children, that does not qualify parent B to file as HOH, because that status stays with the parent who had actual physical custody more than half the nights, and it can't be shared or transferred. You may want to document the childrens' physical living arrangements in writing, such as using a calendar or by saving text messages and emails, showing where they spent the nights, in case of audit.
Lastly, your situation may be very different in 2025. As I said, a dependent only qualifies for HOH if they physically lived in your home more than 183 nights, regardless of any court orders or custody agreements. If you have more than one child, it is possible to arrange custody so that parent A has custody of child 1 for 183+ nights, and parent B has custody of child 2 for 183+ nights, but you actually have to do the math and make the physical living arrangement match the rules. And this is something else you will want to document in writing in case of audit.
