Intercom System Permit Requirements in Missouri

Missouri exempts most low voltage work from electrical contractor licensing requirements, making it one of the more contractor-friendly states for intercom installation. Here's what contractors need to know about licensing, permits, and requirements for intercom systems in the Show-Me State.

State Licensing Exemptions

Under Missouri Revised Statutes Section 324.915, contractors are exempt from electrical licensing requirements for:

• Class 2 or Class 3 remote control circuits
• Signaling or power-limited circuits
• Optical fiber cables or other cabling
• Communications circuits (including raceways)
• Voice, video, audio, and data signal systems

This exemption covers most typical intercom installations in residential and commercial premises.

What's Covered by the Exemption

• Intercom and door entry systems
• Security and surveillance systems
• Access control systems
• Telecommunications and data networking
• Audio/video systems
• Structured cabling

Optional Statewide License

Missouri offers an optional statewide electrical contractor license through the Division of Professional Registration:

• Not required for low voltage work due to exemptions
• Recognized by all political subdivisions in lieu of local licenses
• Useful for contractors working across multiple jurisdictions
• May simplify permitting in cities with local requirements

Contact Information

Office of Statewide Electrical Contractors:
Phone: (573) 522-3280
Fax: (573) 751-6301
Email: OSEC@pr.mo.gov

Local Requirements

While state law exempts low voltage work, local jurisdictions may have their own requirements:

St. Louis

St. Louis has local contractor licensing through the Building Division. Commercial intercom work may require permits depending on project scope. The city maintains its own electrical contractor registration. Check with the Building Division for specific requirements.

Kansas City

Kansas City has local contractor registration and permit requirements through the City Planning and Development Department. Commercial installations typically require permits. The statewide license is accepted in lieu of local licensing.

Springfield

Springfield's Building Development Services handles permits for commercial work. The city follows standard building codes and may require permits for commercial intercom installations.

Columbia

Columbia has permit requirements for commercial electrical work through the Building Regulations Division. Check local requirements for low voltage projects.

When Permits ARE Required

Scenario	Permit Required?	Notes
Residential video doorbell	Usually No	Exempt as low voltage
Residential intercom	Usually No	Exempt as Class 2/3
Commercial intercom	Check Locally	Some cities require permits
Fire alarm integration	Yes	Not covered by exemption
New construction	Yes	Part of building permit

Commercial vs Residential

Residential Intercom

• State exemption covers most installations
• No state license required
• Check local requirements in larger cities
• New construction includes intercom in building permit
• Follow NEC for all installations

Commercial Intercom

• Covered by state low voltage exemption
• Local permits may still be required
• Statewide license useful for multi-jurisdiction work
• Larger projects may need contractor credentials

Insurance Recommendations

While not required by state for exempt work, professional contractors should carry:

• General liability insurance
• Workers' compensation if applicable
• Professional liability coverage
• These may be required by clients or for local licensing

Installation Best Practices

1. Verify local requirements: Check with local building department before starting
2. Consider statewide license: Simplifies working across jurisdictions
3. Follow NEC: Comply with National Electrical Code Article 725
4. Document everything: Keep records for warranty and liability
5. Carry insurance: Good business practice regardless of requirements
6. Stay professional: Quality work builds reputation

Related Permits You May Need

• Access Control Permits in Missouri
• Security Camera Permits in Missouri
• Fire Alarm Permits in Missouri

Frequently Asked Questions

Do I need a license to install intercoms in Missouri?

No state license is required for low voltage work like intercoms due to Missouri's exemption for Class 2/3 circuits. However, some cities have local licensing requirements.

Do I need a permit to install a Ring doorbell in Missouri?

No, wireless video doorbells are exempt from licensing and typically don't require permits in Missouri.

Should I get the statewide electrical license anyway?

If you work across multiple Missouri jurisdictions, the statewide license can simplify operations since all cities must recognize it in lieu of local licenses. For low voltage only work, it may not be necessary.

Can a homeowner install their own intercom system?

Yes, homeowners can install low voltage systems in their own residence in Missouri without licensing or permits in most cases.

Find Intercom Projects in Missouri

Looking for intercom installation opportunities in Missouri? LVN Signal tracks construction permits and bids across Missouri, alerting you to projects the moment they're filed.

Explore Signal

Last updated: February 2026. Requirements may change. Contact the Office of Statewide Electrical Contractors at (573) 522-3280 or local building departments for current requirements.