Short‑Term Rentals (STRs) in Mercer, Missouri: Investor Guide

Overview: Are STRs allowed in Mercer, MO?

No city‑ or county‑specific STR ordinances were identified in the provided content. That means short‑term rentals are not explicitly prohibited in the City of Princeton (Mercer County’s seat) or in unincorporated Mercer County. In practice, an STR can operate as a customary residential use so long as the property meets general zoning, building, and health requirements. Always confirm with local authorities before listing.

How to start a short‑term rental business in this market

1. Confirm zoning and use eligibility

   • City of Princeton: Verify your property’s zoning (e.g., residential) allows transient rentals. If the property is a tiny home on wheels, ensure it is sited in an approved location (e.g., RV park or on a permanent foundation) in line with the state’s tiny‑home framework.
   • Unincorporated Mercer County: There is no county‑wide zoning code per the provided source; confirm any township or parcel‑specific restrictions.

2. Understand building and safety requirements

   • Permanent dwellings: Must meet the International Residential/Building Codes (IRC/IBC) adopted statewide. Tiny homes on permanent foundations (≤400 sq ft) are treated as standard dwellings; minimum ceiling heights, emergency egress, and loft standards apply.
   • Tiny homes on wheels: Generally regulated as recreational vehicles (RVs) and are permitted in RV parks/campgrounds; in residential zoning they typically require placement on a permanent foundation to be used as a dwelling.
   • Obtain any required building/placement permits before construction or installation (e.g., Princeton requires a permit to build; many jurisdictions require permits for structures over 100 sq ft).

3. Address wastewater

   • If sewer is not available, a compliant onsite wastewater treatment system (septic) is required. Missouri’s Department of Health and Senior Services (DHSS) sets standards and permits for septic installations and repairs. Systems must meet state setbacks, soil, and depth requirements.

4. Confirm taxes and registration

   • Local transient guest lodging taxes or city/county “lodging taxes” may apply; status for Mercer County is not specified here. Sales tax registration may be required if taxable lodging occurs. Consult the County Clerk/Collector and the Missouri Department of Revenue to confirm.

5. Licensing and business registration

   • City or county business licenses/occupancy permits may be required; confirm with the City of Princeton and the County Commission.

6. Insurance and hosting platform compliance

   • Maintain appropriate property and liability insurance. Align listings and guest policies with platform standards (e.g., Airbnb/VRBO), localquiet‑hours/noise rules, and occupancy limits.

7. Operations and guest services

   • Provide safe ingress/egress, working smoke/CO detectors (as applicable), fire extinguishers, and clear emergency information. Maintain the septic system per DHSS guidance (pumping schedules, inspections where applicable).

Required documents, permits, licenses, and guidelines

• Site‑specific
  • Zoning verification (city zoning map or county/township zoning confirmation).
  • Building and/or placement permit (for construction, installation, or significant alterations).
  • Septic permit and final inspection (if not connected to public sewer).
  • Proof of utilities connections and compliance with setbacks.
• Operational
  • City and/or county business license (confirm if required).
  • Transient guest lodging tax registration (if applicable).
  • State sales tax authorization (if taxable lodging occurs).
  • STR occupancy/registration documentation (if the city or county adopts future rules).
• Safety/compliance
  • Smoke/CO and fire extinguisher placement logs.
  • Guest information (trash, recycling, quiet hours, parking, emergency contacts).
  • Short‑term rental policy addressing maximum occupancy, events, pets, and noise.

Specific regulations for short‑term rentals (City, County, and State)

City of Princeton (Mercer County seat)

• No dedicated STR ordinance was identified. STRs must comply with:
  • Zoning for transient lodging (confirm with City Hall).
  • Building codes and permits; a permit is required to build in Princeton (per the provided source).
  • Tiny homes on wheels must meet state tiny‑home standards or be placed in an RV park; permanent foundations are required for use as a standard dwelling.

Mercer County (unincorporated areas)

• No county‑wide zoning code (per the provided content). However:
  • Buildings placed or constructed typically require permits through the appropriate jurisdiction.
  • If wastewater is onsite, a DHSS‑permitted septic system is required.
  • Local townships may have additional requirements—confirm parcel‑level restrictions.

State of Missouri

• Adopted IRC/IBC Appendix Q for tiny homes:
  • Tiny homes ≤400 sq ft on permanent foundations must meet minimum ceiling heights (6 ft 8 in living areas; 6 ft 4 in kitchens/bathrooms), emergency egress via skylight/roof window, loft landing platforms, and other standards.
  • Tiny homes on wheels are typically treated as RVs; allowed in campgrounds/RV parks.
• Wastewater:
  • DHSS regulates onsite sewage disposal systems (permits, setbacks, inspections). Local governments may adopt stricter standards (per DHSS rules).
• Taxes:
  • Local transient guest lodging taxes vary by jurisdiction; confirm whether Mercer County or Princeton levies such a tax. State sales tax may apply to lodging transactions.

Contact information (local authority in charge of STRs)

• City of Princeton (Mercer County)
  • Address: 1008 Main St, Princeton, MO 64673
  • Phone: 660-748-4375
  • Website: cityofprincetonmo.com
• Mercer County Commission
  • Address: 802 Main St, Princeton, MO 64673
  • Phone: 660-748-4325
  • Website (general): mocounties.com/mercer-county
• Missouri Department of Health and Senior Services (Onsite Wastewater)
  • Phone: 573-751-6400
  • Website: health.mo.gov/living/environment/onsite
• Missouri Department of Revenue (Business/Sales Tax)
  • Phone: 573-751-3505
  • Website: dor.mo.gov

Links to source pages (where available)

• Tiny home regulations (Missouri general context): www.zookcabins.com/regulations/tiny-home-regulations-in-missouri
• Missouri DHSS Onsite Wastewater Treatment Systems Reference: health.mo.gov/living/environment/onsite/pdf/onsite_ref_book.pdf
• City of Princeton (general city information): cityofprincetonmo.com
• Mercer County information: www.mocounties.com/mercer-county

Notes for investors

• Because no explicit STR ordinance was found, do not assume “no rules apply.” Confirm zoning, permitting, septic compliance, and any lodging taxes before listing.
• If you plan a tiny‑home‑style STR, ensure foundation status and code compliance (permanent foundation vs. RV placement) per Appendix Q.
• Watch for future local rules—more Missouri municipalities are adopting STR registration/licensing and occupancy caps; verify periodically.