In the US, a person living in your unit will often be a tenant. You can have different relationships with your tenants. A house catty-corner across from where I live rents spaces in a two-apartment house, and has an individual relationship with each tenant. Here in Indiana, a judge would have no problem with evicting JUST that tenant. Failure to pay rent when due is an almost insurmountable breach of a tenantu2019s obligations in Indiana and much of the US, and in Indiana you would usually be able to get a tenant out in say three to five weeks. I would go into court right away.Itu2019s also possible to have a collective agreement with a whole group of people. There, one person is responsible for ALL of the rent, OR all tenants have to pay it by chipping in: either/or. If this is a u201cjoint tenancyu201d of that sort, then the one tenantu2019s failure to pay is the failure of all of them to pay, and your remedy is to evict all of the tenants. [Of course, you can probably - at least in Indiana, and possibly much of the rest of the US - simply fail to go through with the eviction for the two or three tenants you DO like, and only boot out the one whou2019s the trouble-maker. Itu2019s not discrimination - treating neu2019er-dou2019wells badly and nice people nicely is not invidious discrimination under American law.]Sadly, in the second scenario above - but not the first - the judge might determine that youu2019ve been taking partial payments. If youu2019ve done it long enough, you have reformulated the contract, and you might be stuck for that period of time. To be safe, what you should do is just send a Notice of Change in Terms of Tenancy to all tenants [possibly by registered letter, though an email without a bounce-back might do just fine in many places] indicating that, in the future, no partial payments will be accepted. If the neu2019er-do-well then continues not to chip in, refuse the rent from all parties, move to evict everyone, tell the good tenants that the action against them is only a formality, get the neu2019er-do-well out by sheriffu2019s action, and let the good tenants stay under a new agreement.As a side note, when I was a landlord, I never rented person-to-person. I made groups of roommates - in the rare cases I accepted tenancies from them - sign a joint agreement.