In 2016 I lived in a single-bedroom rental apartment in Delaware, USA. My brother needed a place to stay, so we agreed that he would pay me a reasonable amount each week to take over my living room. This was all informal, on a week-by-week basis, and he lived with me for 4–5 months.
Now, seeing as this was a one-bedroom apartment and he was camped out in my living room, this was an informal arrangement, and he's my brother, was the rent money he paid me "income", or were we just "splitting the rent", as it were?
In other words, if I'm being honest (and I want to be), should I report the money I "earned" as income on my tax return? Right now, I'm leaning on just not reporting it for the reasons above, but I'm not entirely sure.
Note that the amount of money in question was around $1500, which he paid in cash.
Somewhat related: If I'm the only one on the mortgage, do I have to count my significant other's payments as rent for tax purposes? (one comment stands out: "Think about it: If my brother stayed with me for six months, and made some contributions toward his keep while he was here, is it really necessary to call it a rental for that duration?"