Code 33 commonly means that a radio channel is reserved for emergency traffic in the California agency documents collected here. CHP describes clearing radio channels for emergency traffic; Alameda and Arcata use comparable definitions. The code concerns communication priority rather than a specific offense.
Code 33 Meaning by Agency
The wording below ranges from clearing the channel to holding non-emergency transmissions. These agency definitions support the shared emergency-traffic theme while retaining their local phrasing.
| Agency or list | What Code 33 means | Source |
|---|---|---|
| Alameda Police Department (CA) | Clear air for emergency transmissions | Alameda PD dispatcher program |
| Albany Police Department (CA) | Emergency situation, hold non-emergency radio traffic | Albany PD communications manual |
| Arcata Police Department (CA) | Emergency radio traffic only | Arcata PD communications manual |
| California Highway Patrol (CA) | Clear radio channels for emergency traffic | CHP aural brevity card |
| Chowchilla Police Department (CA) | Emergency traffic only | Chowchilla PD dispatch manual |
| Cotati Police Department (CA) | Do not transmit; emergency | Cotati PD communications manual |
| San Jose Police Department (CA) | Emergency - do not transmit | San Jose PD 10-code guide |
| Sebastopol Police Department (CA) | Channel restriction | Sebastopol PD dispatch manual |
| Yuba City Police Department (CA) | Emergency, clear channel | Yuba City PD dispatch manual |
Why a Channel May Be Restricted
Radio conversations share airtime. A direction to hold non-emergency messages leaves room for important updates. That describes the purpose of the code without specifying a particular incident, such as a pursuit, an officer-assistance request or a medical call.
A scanner listener should not infer the event type from Code 33 alone. It tells you something about how the channel is being used. Other words or records are needed to establish what prompted the restriction.
A Channel Marker in the Santa Barbara Procedure
The Santa Barbara County Sheriff's published Code 33 and Channel Marker procedure documents a channel-marker process alongside the emergency restriction. The marker is an agency-specific procedural detail, rather than proof that every system will sound the same.
A tone heard on a recording is not enough to identify a particular code without knowing the radio system and its procedure. Likewise, the absence of a recognizable tone does not prove routine traffic is permitted. This page explains the terms and does not direct radio operation.
Code 33 Is Different from Code 3
Code 3 often describes an emergency response or operating mode. Code 33 in the documents here describes emergency-only radio traffic. An event can involve both, but one does not define the other.
For example, an agency can have units responding to an emergency while dispatch also limits routine channel use. That sequence contains a response decision and a communication decision. Keeping them separate avoids translating every emergency-related number into lights and sirens.
Code 33 and 10-33 Are Related Searches, Not Identical Labels
The 10-33 comparison documents emergency traffic or help-related meanings in its own lists. A reader searching 1033 may be asking about that 10-code form, while a recording explicitly saying Code Thirty-Three is a different label.
Do not silently add or remove the prefix. Some codebooks may have similar concepts, but that does not make the entries interchangeable for every department. The 10-code guide and scanner-code guide keep the two families identifiable.
What the Code Does Not Tell You
Code 33 does not by itself prove an officer is injured, identify a suspect, establish a legal charge or explain the final outcome. It also does not say that all activity at an incident has stopped. It describes which radio traffic has priority in the named systems.
Use the agency's document for the exact local rule and the main hub to identify an unfamiliar code family. When a list is from a different period or department, keep that limitation attached to the definition.
FAQ
Does Code 33 mean emergency traffic only?
That is the shared theme in the cited CHP and California city documents, with local wording differences.
Does Code 33 mean lights and sirens?
It concerns radio-channel priority in these sources. Code 3 commonly describes an emergency response.
Is Code 33 the same as 1033?
1033 may be an unhyphenated form of 10-33. Retain the prefix rather than assuming the two labels are identical.
Does Code 33 prove an officer is down?
No. A channel restriction does not establish the cause of the emergency or an injury.
Is a tone always required?
The Santa Barbara procedure documents a channel marker, but that should not be assigned to every agency without its own supporting rule.
Sources
- Public Safety Dispatcher Training Program (radio codes, pp. 8-9), Alameda Police Department. Official Checked October 2026
- Communications Training Manual (radio codes, pp. 20-22), Albany Police Department. Official Checked October 2026
- Communications Training Manual (radio codes), Arcata Police Department. Official Checked October 2026
- CHP 254 – Aural Brevity Card (01-2021 v2), California Highway Patrol. Official Checked October 2026
- Communications Training Manual (radio codes), Chowchilla Police Department. Official Checked October 2026
- Communications and Records Training Manual, Cotati Police Department. Official Checked October 2026
- SJPD 10-Codes (study guide), San Jose Police Department. Updated 10/15/18. Official Checked October 2026
- Dispatch Training Manual, Sebastopol Police Department. Updated April 28, 2022. Official Checked October 2026
- Communications Division Training Manual (radio codes, pp. 20-21), Yuba City Police Department. Updated November 2023. Official Checked October 2026
- Code 33 & Channel Marker (dispatch procedure), Santa Barbara County Sheriff's Office. Updated Procedure update 9/27/2016. Official Checked October 2026