San Francisco runs the oldest active short-stay regulatory regime in California. Hosts register with the Office of Short-Term Residential Rental Business, file Transient Occupancy Tax (TOT) returns quarterly, and carry a Business Personal Liability Insurance certificate on file with the city. The city’s Business and Tax Regulations Code, Section 41A, is the line that ties each of those requirements together — the permit exists at the intersection of registration, insurance, and tax.
The Business Personal Liability Insurance certificate
The city requires every registered host to hold a Business Personal Liability Insurance policy with minimum coverage of $500,000 per occurrence, and to keep the certificate on file. A cancellation or lapse triggers automatic deactivation on every booking platform that pulls the city’s permit list. The certificate is reviewed at renewal and at any complaint-driven audit, and it must be re-filed whenever the named operator, the address, or the policy limit changes.
Most host-side lapses aren’t from missing the certificate entirely — they’re from letting it expire during a quiet renewal quarter. The fix is a renewal radar that fires before the policy lapses, not after.
The 90-day unhosted cap and the Hosted Rental carve-out
Unhosted short-stay rentals in San Francisco are capped at 90 days per year, across all platforms combined. Hosted Rentals — where the host is on-site for the stay — are uncapped. The cap is enforced retroactively against the city’s own reservation filings, so a calendar that lets the operator go over 90 days produces a violation regardless of whether the bookings were accepted.
Operators with more than one unit need a per-unit calendar that knows the cap threshold and stops proposing unhosted nights past it. The Hosted Rental carve-out is only available when the host of record — the human on the permit — is present, which means AI tooling cannot book Hosted Rental nights on the operator’s behalf; only the operator can, by marking themselves on-site.
TOT registration, quarterly filing, and what an audit looks like
Registered hosts charge a 14% Transient Occupancy Tax on every booking under 30 days, remit it quarterly, and keep a ledger that reconciles to the booking-platform payouts. The Treasurer & Tax Collector’s office runs an audit cycle that pulls booking-platform exports, cross-checks them against TOT returns, and re-computes the differential. A clean ledger answers an audit with a report; an inconsistent ledger answers it with a bill plus a penalty.
RentaraAI pulls the booking-platform ledgers, drafts the TOT return, and flags the per-quarter differential before it goes out. We don’t sign the return — the named human operator does — but the difference between a five-minute review and a multi-week audit is exactly this kind of pre-filing reconciliation.