Renewal every two years: the expiration date, what it costs, the 90-day retroactive window, the five-year cliff, inactive status, and what an expired day does to your right to be paid
In one paragraph
The license you worked for expires on a date CSLB set the day it issued, two years out, on the last day of a month, and nothing about the renewal is automatic. This lesson gives the mechanics as the statute writes them: when the license expires, what a timely renewal costs a C-10 in 2026 including the $20 electrician-certification surcharge, what happens on the day after expiration (you are unlicensed, with everything that means), the 90-day window in which a late renewal is made retroactive as if it never lapsed, the delinquency fee at 50 percent, the five-year cliff after which the number is gone and you start over, the option of an inactive license when you are not contracting, and the reason all of this matters more than a fee: an unlicensed day inside a job means you cannot sue to collect for it and the customer can sue to take back what they paid.
The rule
A license expires two years from the last day of the month in which it was issued or last expired, and renewal before that date continues it for two years (B&P 7140); an expired license may be renewed within five years with the delinquency fee, but the licensee is unlicensed from expiration until an acceptable renewal is filed (7141), except that a complete renewal delivered or postmarked within 90 days of expiration is granted retroactively (7141.5). The delinquency fee is 50 percent of the renewal fee (7137(a)(5)); a C-10 pays $20 more with each active renewal for electrician certification enforcement (7137(a)(6)(A)); current CSLB fees are $470 timely for a C-10 sole owner and $720 for an entity, $695 and $1,070 delinquent. After five years a new application is required (7141(d), 7143.5). A contractor not duly licensed at all times during a job cannot sue to collect and the customer may recover everything paid (7031(a)-(b)), and contracting unlicensed is a misdemeanor (7028).
Why it matters
A contractor whose renewal notice went to an old address, or sat in a pile, can work for weeks in 'expired' status without knowing it. Under 7031 each of those days is a day the customer can refuse to pay and sue to get back what they already paid, and under 7028 each is a misdemeanor. The renewal is a form and a fee; the consequence of missing it is the business. This lesson exists so the date is on the calendar and the 90-day rescue is understood before it is needed.