Rialto California ZIP Codes

Rialto holds 2 ZIP codes, all inside one county and one postal prefix.

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the Rialto codes above are listed without a column we would have to invent.

Scope every ZIP code recorded for Rialto. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. ZIP codes are delivery-route groupings, not areas; the boundaries implied by any ZIP map are approximations.

Every Rialto ZIP code begins 923. Those first three digits identify the sectional center facility that processes mail for this part of California. Statewide that range covers 74 ZIP codes, so Rialto accounts for 3% of it.

Every California ZIP prefix and the region it covers →

ZIP codes and area codes are separate systems — one routes mail, the other routes calls — and they do not share boundaries. The codes below serve the same ground Rialto occupies.

• 840 Area code 840
• 909 Area code 909

Rialto California area codes in full →

Straight-line distance between place reference points, not driving distance.