Sorry, just now seeing this. Do you have title?
Also you want to register under “Permanent
Trailer Identification” (PTI) program. 15ft and under.
I was told it was $5 per year, but this says $10..... Anyway it's MUCH cheaper than an annual registration and is every 5 years.
https://www.dmv.ca.gov/portal/handbo...endix-1f-fees/
Here are some other links:
https://www.dmv.ca.gov/portal/file/p...-reg-4017-pdf/
https://www.dmv.ca.gov/portal/handbo...ification-pti/