Sources: census record as of October 19, 2026; authority and insurance from FMCSA L&I, checked October 4, 2026; inspections and crashes from FMCSA SMS, checked October 4, 2026.
Quick answer
503 Corporations LLC is an interstate motor carrier in San Antonio, Texas (USDOT 4315389) with active operating authority and a self-reported fleet of 1 power unit.
Key takeaways
USDOT 4315389 is registered to 503 Corporations LLC, an interstate carrier based in San Antonio, TX.
MC docket number on file: MC-1691281.
Operating authority status: authorized (Contract), with $750K BIPD insurance on file.
Self-reported fleet size: 1 power unit and 1 driver (FMCSA MCS-150 self-report; sanitized for plausibility).
3 of 9Vehicle inspections with an out-of-service orderToo few inspections for a meaningful rate
3 of 11Driver inspections with an out-of-service order27.3%
Source: FMCSA Safety Measurement System, roadside inspections and crashes over a ~24-month window, checked October 4, 2026. An out-of-service rate is the share of inspections in which a vehicle or driver was placed out of service. With few inspections, one result moves the rate a lot. FMCSA crash records include crashes regardless of fault. None of these figures is a safety rating. The official Satisfactory/Conditional/Unsatisfactory safety rating is issued separately. See SAFER.
About 503 Corporations LLC
503 Corporations LLC is an interstate motor carrier based in San Antonio, Texas, registered with the FMCSA under USDOT 4315389. It holds active operating authority (MC-1691281), with $750K of BIPD insurance on file. The carrier self-reports a fleet of 1 power unit and 1 driver. Registered cargo includes general freight. Its most recent MCS-150 filing reported 125,000 mi (2025).
Before you work with this carrier
Confirm the safety rating. Authority and insurance are shown or linked above. Open the SAFER snapshot for the official safety rating and out-of-service status.
Verify insurance is current. Coverage on file can lapse; confirm active BIPD/cargo before tendering a load.
Match authority to the work. For-hire loads need active operating authority. A USDOT number alone isn't enough.