One tenant signs the lease. Six months later there are two sets of shoes by the door, a second car in the lot, and a water bill that looks like it feeds a small family. Nobody told you, and nobody was screened. If you own a rental here in Denver, you will probably face this at some point. How you handle the first few weeks decides whether it's a short conversation or a court case. Most of the fix starts with a solid lease agreement, and the rest is timing, paperwork, and a calm tone. This post is for owners and small landlords who want a clear order of operations. We'll cover how to spot an extra occupant, what Colorado's notice rules say, what you must never do, and when it makes sense to hand the whole thing to someone else.

In This Guide

Why Extra Occupants Show Up in the First Place

Most of the time it isn't scheming. It's life.

The rental market here is transient. Young professionals, students, and people on short job contracts move in and out all the time. In neighborhoods like Capitol Hill, RiNo, and Central Park, informal subletting and "just staying a few weeks" arrangements are common. Near the University of Denver, we see a pattern where one student signs the lease and friends quietly move in later.

The usual ways it starts look like this:

• A partner moves in. It starts as a few nights a week and becomes every night.
• A roommate swap. One leaseholder leaves and a friend takes the room without applying.
• A family member "for a bit." Someone between jobs or apartments never leaves.
• An informal sublet. The tenant travels for work and rents the bedroom to cover costs.

Unauthorized occupants are on the list of tenant issues we handle directly, right next to late rent and noise complaints. They are not rare.

How to Spot One Before It Settles In

You can't fix what you don't see. A few signals tend to show up early.

• Utility jumps. If you pay any utilities, a bill that climbs for three straight months is a flag.
• Extra vehicles. A second or third car that parks overnight, every night.
• Names on the mailbox or door. Packages addressed to people who aren't on the lease.
• Neighbor comments. Neighbors usually know who lives where.
• Wear that doesn't match the lease. Faster carpet wear, full trash, more noise.

Here's a take most landlords won't love. Your lease clause on occupants is only as good as your inspection schedule. The clause gives you the right to act. Regular visits are what let you act while the problem is still small.

Property visits are part of how we manage a home, with no per-visit charge. That gives us natural, regular chances to notice when a one-person unit starts looking like a three-person unit. It also gives us dated notes to work from if a notice becomes necessary.

Check the Facts Before You Say a Word

A guest who stays a weekend is not an occupant. A person who has lived there for two months might be. Before you contact the tenant, write down what you actually know.

1. Dates. When did you first notice signs, and what were they?
2. Evidence. Photos from a property visit, utility records, and anything neighbors told you.
3. The lease language. What does your lease say about occupants and guests, and about guest stay limits?
4. Who is on the lease. Every adult who applied and was screened, by name.
5. Communications. Any texts or emails where the tenant mentioned a roommate or partner.

This is where your software matters. We run owner portals on DoorLoop, so lease documents, maintenance records, and communications live in one place with timestamps. When a manager or attorney asks "when did this start?", you can answer with records instead of memory.

Start With a Written Conversation

Most of these situations end here, and they should. The goal is to get the unit back to a compliant setup, with a paper trail behind it.

Contact the tenant in writing. Keep it plain and non-accusatory. Say you've noticed someone else appears to be living in the home, point to the occupant clause in the lease, and ask them to call you.

Then offer the two real outcomes:

• The person moves out. Set a date in writing.
• The person applies. They go through the same screening as any applicant. If they pass, you add them to the lease with a signed addendum.

Notice what's missing, which is a free pass. A person who lives in your home needs to be screened, on the lease, and accountable for the rent and the condition of the home. When our leasing agent Gavin walks a tenant through a lease, the occupant clause is one of the pieces he points out. Setting that expectation on day one makes this conversation far easier later.

One owner who had us place a tenant in his townhome described the experience as including "accurate and timely communication, collaboration, and fair compromise." That mix is the right tone here too. Be clear on the rule, fair about the path back to compliance, and quick to put everything in writing.

What Colorado Requires Before You Can File

If the conversation goes nowhere, you can't just file for eviction. Colorado treats an unauthorized occupant as a non-rent lease violation. You have to give the tenant a written notice first, with two choices. They can fix the violation, for example by having the person move out or by adding them to the lease properly. Or they can give up possession.

How Many Days Does the Notice Give?

For most residential leases, the notice has to allow 10 days. A few shorter periods exist, but only in narrow cases.

The 5-day period is narrow. It covers a single-family home leased by a landlord who owns five or fewer single-family rentals, and the lease itself must say the 10-day period doesn't apply. It is not for apartments or for every small landlord. The statute behind all of this is C.R.S. § 13-40-104.

What If the Occupant Comes Back?

Say the tenant got a notice, the person moved out, and a month later they're back. Colorado handles repeat violations differently. If a tenant already received a notice to fix a violation and breaks the same lease term again, you can end a residential tenancy with a written notice to quit. It takes effect 10 days after service, and the tenant doesn't get another chance to fix it. The exempt-agreement and employer-housing periods are shorter, as in the table above.

Serious Violations Follow a Different Track

Colorado also has a category called substantial violations, defined in a separate statute section. If you want to treat an unauthorized occupant as one, the notice rules come from that section, not the ordinary 10-day notice. We won't try to summarize those rules here. Check the current statute or call an attorney.

What You Can't Do

This is where well-meaning owners get hurt. The frustration is real, and the shortcuts are tempting.

Other limits to keep in mind:

• Domestic violence. A lease-violation eviction can't go forward if the violation was caused by or resulted from domestic violence or abuse against the tenant, documented by a police report or a valid protection order. A lease can't waive this. You can still seek possession against the abuser. If the "unauthorized occupant" is the abuser, talk to an attorney before you move.
• Non-renewal isn't a free exit. Don't assume you can just decline to renew to get rid of an occupant. Colorado's 2024 for-cause eviction law limits non-renewal, so check the details with counsel first.
• Fair housing. Apply your occupancy rules the same way to everyone. Before you treat someone as unauthorized, make sure they aren't a live-in aide tied to a disability accommodation request, and that your rule isn't landing harder on families with children. For a first violation, a HUD administrative law judge can impose a civil penalty of up to $26,262.
• Local rules. Check current city rules on occupancy and rental licensing, including Denver rental license requirements, before you quote any occupancy cap to a tenant.

The "Stay a While" Trap

A common owner mistake is a casual verbal okay. A tenant mentions a partner needs a place for a bit, and the owner says sure.

Picture a landlord who manages a rental on their own and tells a tenant a partner can "stay for a while." A year later, the partner is still there and was never screened. The original tenant wants to move out. Now the owner has an unscreened adult living in the unit, no lease with that person, and no record of when it began. An occupant who has lived somewhere for months may be able to claim they're a tenant, which can mean a formal eviction. Once you add attorney fees, court costs, lost rent, and turnover, that process can easily cost thousands of dollars.

Run the numbers on a home renting for $3,000 a month, which is our portfolio average. Say the case drags on for two months. That's $6,000 in rent exposure before you pay a single legal fee. Docket timing at the county court adds delay between filing and hearing, so the sooner you document and act, the less you lose.

Most owners who look the other way are protecting a good tenant relationship. We get it. But the longer an unreported occupant lives in the unit, the harder and costlier the fix gets.

If someone really does need to stay, put it in writing. Use a dated addendum that names the person, states the end date, and spells out the rules. Better yet, screen them and add them to the lease.

Build Prevention Into the Lease and the Calendar

You can't prevent every surprise, but you can make surprises rare.

• List every adult on the application. Anyone 18 or older who will live there gets screened.
• Write a clear guest limit. Pick a number of nights, put it in the lease, and apply it evenly.
• Define the remedy. Make sure the lease says what happens if someone moves in without approval.
• Schedule visits. A property visit once or twice a year catches most problems early.
• Keep records in one place. Dated photos, notes, and messages in your owner portal.

When It Makes Sense to Bring in a Manager

Plenty of owners handle this on their own and do fine. But if you don't have time to visit the property, keep records, and serve notices on the right timeline, this is the kind of problem management is built for.

We've been in business for 15 years and manage around 60 properties, including single-family homes, multi-family buildings, townhomes and condos, and student housing. Student housing is where occupant creep is most likely, and where early visits matter most. Jenny Usaj, who owns the company, built our process around catching small lease problems before they grow.

Pricing is simple. Our management fee is a flat, all-inclusive 10%. That covers lease enforcement coordination, with no per-visit inspection charges and no maintenance markups. Leasing is one month's rent, backed by our written Leasing Guarantee. If a tenant we place doesn't work out in the first year, we re-lease the property and the leasing fee is on us. Full terms come in writing before you sign.

If you're comparing the best property management companies in Denver, ask each one for its complete fee schedule, every fee in one document. Compare line by line, especially inspection fees and repair markups. Good Denver property management should make your life simpler, with fees you can read in one sitting.

If an extra occupant feels harder to handle than it should, we're open to a conversation.

FAQ

How much notice do I have to give for an unauthorized occupant in Colorado?

For most residential leases, the written notice has to give the tenant 10 days to fix the violation or give up possession. Shorter periods apply only in narrow cases, such as 5 days for qualifying exempt residential agreements and 3 days for employer-provided housing.

Can I change the locks or shut off utilities to remove an unauthorized occupant?

No. In Colorado, you recover possession through the court eviction process, not by locking people out, cutting utilities, or removing belongings. Self-help can expose you to a lawsuit.

Can I add the extra person to the lease instead of evicting?

Yes, and it's often the cleanest outcome. The person applies, goes through the same screening as any applicant, and signs a lease addendum if approved.

What if the occupant moves out and then moves back in?

If a tenant already got a notice to fix the violation and breaks the same lease term again, you may be able to end the tenancy with a written notice to quit. In most residential cases that takes effect 10 days after service, with no second chance to fix it.

How long can a guest stay before they count as an occupant?

It depends on what your lease says, so set a clear guest limit in writing and apply it evenly. If a guest has stayed for weeks or months, talk to an attorney before you act, since long-term occupants can raise tenancy claims.

Should I talk to an attorney before serving a notice?

Yes, especially if the notice involves a repeat violation, a possible substantial violation, or any hint of domestic violence. The wrong notice type can cost you weeks, and a short consultation is cheap next to a dismissed case.