Legal Question in Landlord & Tenant Law in Massachusetts

Re: Eviction/tenant

It appears to me that you are your sister's and brother-in-law's sole tenant, especially if the rent comes solely from you. In this case, your daughter and her boyfriend are subtenants at best. You can simply give a thirty-day notice to each of them, telling them it is time to go. After that, you would seek a summary process action if they chose not to move.

If your sister and brother-in-law consider them tenants of theirs, they would do this.

It is probably possible to argue that they are not tenants, but mere guests, but the long-term nature of the arrangement might make this a waste of time and energy. The thirty-day notice is a conservative but safe way to get them out. Indeed, the thirty-day notice could be used to give you an "out" if all of the tension is financial: you can offer a "new tenancy" at an amended rent, giving them the choice of paying in a specific amount per month.

Good luck. Seek a local attorney.

Also, you should be aware that you have the right to seek an Abuse Prevention Order ("restraining order") under c. 209A against either if either is making a significant and real threat putting you in fear of bodily harm. Such an order, if issued, would require them to immediately move out. C. 209A expressly applies to both family members and co-tenants, so do not allow anyone to misinform you. Again, however, it must be more than mere fighting or bad blood.