Before you start

A valid visa or other admission category
An electronic I-94 record from the CBP website
Work authorisation from DHS for a Social Security number
A California address for the DMV and most account applications

Step-by-step

1
Download your I-94 in the first few days
It records your admission class and 'admit until' date. Retrieved electronically from the CBP website. This matters more here than elsewhere because you will present yourself to CBP repeatedly.
OnlineWho: YouWeek 1
2
Wait about ten days, then apply for a Social Security number
SSA verifies your status against DHS systems that lag entry by one to two weeks. File Form SS-5 in person with your passport, visa and I-94. There is no fee.
In personWho: YouFrom ~day 10Free
3
Understand what crossing the border does to your status
Leaving the US and returning is a new admission. If your visa has expired — even though your I-94 is current — you generally cannot re-enter without a new visa. A day trip to Tijuana can therefore strand you outside the country. Check both your visa validity and your I-94 before any crossing.
OnlineWho: You
4
Consider SENTRI if you will cross regularly
The trusted-traveller programme gives dedicated lanes at San Ysidro and Otay Mesa, cutting waits dramatically. Non-citizens can apply, though eligibility depends on status and nationality. Vetting takes months, so start early.
OnlineWho: You
5
Book a DMV appointment before you arrive
California's ten-day licence deadline collides with appointment availability. Booking from abroad is the standard workaround; inland offices in El Cajon or Escondido are often sooner than coastal ones.
OnlineWho: YouBefore arrival
6
Ask for REAL ID, not a standard licence
Since 7 May 2025 a standard California licence cannot board a domestic flight. Note that a REAL ID is not a border document — you need a passport or a trusted-traveller card to re-enter from Mexico.
In personWho: You

Documents you’ll need

Passport with valid visa
I-94 admission record from the CBP website
Form SS-5 for a Social Security number, or IRS Form W-7 for an ITIN
Employment authorisation document or approval notice, where applicable
Passport or trusted-traveller card for every border crossing

Things most newcomers don’t know

A day trip to Tijuana can end your stay in the United States.

Your I-94 governs how long you may remain; your visa governs whether you may re-enter. If the visa has expired while you are lawfully present on a valid I-94 — an entirely normal situation — leaving means you cannot come back without applying for a new visa abroad. In San Diego, where crossing is casual and cheap, people do this by accident. Check both dates before any crossing.

Source: US Customs and Border Protection — I-94 record

SENTRI is the highest-value $122 in the city.

Northbound waits at San Ysidro routinely run one to three hours; SENTRI lanes cut that to a fraction. Over five years, for anyone crossing even monthly, the time saved is measured in days. Vetting takes months, so the mistake is applying after you have started crossing rather than before.

Source: US Customs and Border Protection — SENTRI

Living in Tijuana while working in San Diego is common and complicated.

Tens of thousands do it, drawn by rents a fraction of San Diego's. But it requires status that permits it, a workable crossing routine, and care about tax residency and where you are deemed to live for licensing and insurance. It is a real option and not a casual one — get advice specific to your visa category first.

Source: community-reported

California issues licences regardless of immigration status.

Under AB 60 the DMV grants licences to applicants who cannot prove lawful presence. Such a licence cannot be used to fly or to cross the border, but it allows legal driving and insurance. In a border county this is a significant and widely-used provision.

Source: California DMV — AB 60 driver licences

Common mistakes to avoid

Crossing into Mexico on an expired visa and being unable to return.
Applying for SENTRI after you have already started crossing weekly, and waiting months.
Assuming a REAL ID licence works as a border document — it does not.
Arriving without a DMV appointment inside California's ten-day deadline.
Visiting a Social Security office before DHS records have synced.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.