It's frustrating when roommates don't work out, especially if a roommate refuses to pay rent, damages the building, or doesn't even have a lease agreement. Colorado's Landlord and Tenant Act provides provisions for legal eviction, and there are some situations that allow you to evict the roommate without getting the landlord involved.

A roommate who is on the landlord's lease requires the landlord to evict him. A roommate who has an agreement with you is considered your subtenant. A subtenant has specific obligations under the Colorado Landlord and Tenant Act to his landlord, which in this case would be you. A subtenant who violates the lease agreement, for example by not paying rent, or who is at the end of a lease term can be evicted by the master tenant.

​Read More:​ How to Evict a Subtenant

Colorado requires a landlord to have a legal reason to end the tenancy. The legal reasons are provided in Colorado's Landlord and Tenant Act. Unpaid rent and breach of a lease term are the two main eviction reasons. The only way a landlord can evict a tenant without cause is at the end of a lease term.

​Read More:​ How to Get Rid of a Roommate Legally

There is a notice requirement to fulfill before bringing the eviction case to court. You must provide the roommate with a written notice explaining the eviction cause, whether it is for unpaid rent, a breach of a lease term or both. The written notice for unpaid rent and lease violations is called Demand For Compliance Or Right to Possession. It gives the roommate three days to pay rent, and/or comply with any other breached lease term, or leave. If the roommate does not comply with the stated demand within three days of receiving the notice, the landlord may start the process of eviction with the court.

For eviction without cause, such as when it's coming to the end of the lease term and you simply no longer wish to lease to the person, you must serve a Notice to Quit. You must serve the Notice to Quit within a certain time frame before the end of the lease. For example, for a lease agreement that is for one year or longer, you must serve the notice at least 91 days before the end of the lease.

Filing an eviction complaint is the next step in the eviction procedure. If the roommate refuses to move out, you'll need to go to the Justice Court that controls the jurisdiction of the property and file for a Forcible Entry and Detainer. This is a court order that permits a sheriff to remove the subtenant from the property. A court clerk has all the paperwork that you need. You'll also provide copies of the written lease agreement, the written notice and anything that proves the eviction cause such as unpaid rent invoices.

A summons form is filed with the Detainer suit, and the hearing date is entered on it by the court clerk. Unlike the written notice, another person needs to serve the roommate with the court summons. The court can direct you to a process server, such as a private process server or a sheriff. Improper service gives the roommate grounds to contest the eviction, so timely service is essential.

The eviction hearing has both the subtenant and master tenant presenting evidence to support his case. With the master tenant, this would include such items as lease agreements, rental invoices and anything else justifying the eviction cause. In most cases, a default judgment is granted to the landlord, due to invalid defense or no appearance by the tenant. A Writ of Restitution can be filed for if the roommate refuses to leave after judgment is granted. This permits a sheriff to go on the property to remove the roommate from the rental unit.

​Read More:​ A Renter's Rights in Colorado