Sylmar CA ZIP Code Overview
Sylmar is a neighborhood in Los Angeles, California, served by multiple ZIP codes depending on exact location and mail delivery point. While 91342 is the primary ZIP code listed for Sylmar by the USPS, mailers may also encounter adjacent codes such as 91390 for post office boxes. Around 161,000 people live in the broader Sylmar area, which is part of the San Fernando Valley. Below is a quick reference table showing ZIP codes by common area names and USPS delivery characteristics.
| Area / Neighborhood | ZIP Code | Type | Key Notes |
|---|---|---|---|
| Sylmar (general) | 91342 | Standard | Main delivery ZIP for most residential and commercial addresses |
| Sylmar Post Office | 91390 | PO Box | Used for post office box customers in Sylmar |
| Sylmar (near boundary areas) | 91311, 91304, 91356 | Adjacent | Nearby ZIP codes that sometimes intersect mailing routes or community perceptions |
What Is a ZIP Code and Why It Matters for Sylmar
A ZIP Code helps the U.S. Postal Service route mail efficiently to a specific sector, city, or rural area. In Sylmar, 91342 directs mail to the general region within Los Angeles, while 91390 handles post office box mail. Using the correct ZIP Code reduces delays and misrouted items. When signing up for services or filling out forms, always use the ZIP Code that matches your street address to ensure timely delivery.
Geographic Boundaries and Service Area
Sylmar lies in the northeastern San Fernando Valley, bordered by areas such as Granada Hills, Mission Hills, and the Santa Susana Mountains. These natural and municipal boundaries can affect which ZIP Code applies to a given street. The USPS relies on delivery routes and city suffixes to determine the final code, so addresses near community borders may share characteristics of multiple ZCTA boundaries.
Key Geographic Markers
- Northern boundary: proximity to Santa Susana Mountains and Los Angeles County open space.
- Southern boundary: transition toward Pacoima and other San Fernando Valley neighborhoods.
- Eastern and western limits: generally marked by major thoroughfares and natural terrain features.
Area Codes and Additional Identifiers
Sylmar uses area code 818, which covers much of the San Fernando Valley. The 747 overlay also serves the region. While area codes are not part of the ZIP Code system, they are useful for phone services and can confirm you are reaching local numbers when coordinating mail or deliveries.
Quick Reference: Area Codes and ZIP Codes
| Service | Code | Purpose |
|---|---|---|
| Postal | 91342 (main), 91390 (PO Box) | Mail routing and delivery |
| Telephone | 818, 747 overlay | Local and long-distance calling |
Practical Tips for Sending Mail in Sylmar
- Always verify the full address, including the correct 5-digit ZIP Code, before sending packages or letters.
- Use 91342 for most residential and business mail unless the post office directs you otherwise.
- For post office boxes in Sylmar, use 91390 to avoid delays in box retrieval.
- When using mapping or navigation apps, confirm the ZIP Code listed matches your destination street.
- If you are moving, update your address with the USPS and local vendors to ensure uninterrupted service.
Common Questions About Sylmar ZIP Codes
Because community names can carry multiple ZIP Codes in public understanding, residents sometimes ask whether nearby codes like 91304 or 91356 apply to their street. In most cases, 91342 is correct for Sylmar proper, but cross-boundary streets may fall under adjacent ZCTAs. The USPS provides the most authoritative data for specific addresses through their ZIP Code lookup tool.
Reliable Sources and Further Reading
For the most current and address-specific ZIP Code, consult the official USPS website and their ZIP Code lookup tool. Local post offices can also confirm delivery details for particular streets or developments in Sylmar. Use these resources when filling out official forms or updating contact information.