San Marcos, CA Short-Term Rentals: Primary-Residence-Only Rule (2026)

Many cities that license short-term rentals restrict whole-home rentals to an owner's primary residence or cap them through tiered programs (as the City of San Diego does with its STRO tiers). Unincorporated San Diego County has no such requirement because it has not adopted an STR ordinance. There is no primary-residence mandate, no owner-occupancy condition, and no requirement that the host live on-site to register or operate. The County's only STR-specific obligation is registering for and remitting the 8% Transient Occupancy Tax, which applies regardless of whether the property is the operator's home. One related state-law limit does apply to accessory dwelling units: under California ADU rules adopted by the County, an ADU may not be rented for stays of fewer than 30 consecutive days, so a backyard ADU cannot lawfully be used as a short-term rental even though the main dwelling can. Otherwise, whole-home and investor-owned short-term rentals are permitted under County law subject to zoning, building, fire, and noise compliance. Because no County ordinance imposes a primary-residence rule, any statement that unincorporated STRs must be owner-occupied would be inaccurate.