If you've lost every key to your car, the vehicle needs a brand-new key "originated from scratch," which is a different and more involved job than cutting a spare from an existing key. A mobile automotive locksmith in San Jose can typically do this at your location, but you'll need to prove ownership first and the vehicle's ignition system must be accessible. Cost and timing vary widely depending on your vehicle's make, year, and key technology (basic transponder vs. proximity/smart key), so any real number comes only after the locksmith identifies your exact vehicle. Timing is always confirmed by phone — never guaranteed in advance — since parts availability and job complexity differ case by case.
There's a meaningful difference between "I have one key and need a spare" and "all keys lost." When you still have a working key, a locksmith can often read data directly from that key or from the vehicle's existing programming to duplicate it quickly. When every key is gone, there's nothing to copy from. The locksmith instead has to originate a new key from zero — determining the correct blank, cutting it to match the lock (if the vehicle still uses a mechanical cylinder), and then programming that new key into the car's immobilizer or security system so the engine will actually recognize it and start.
This is a more technical process. Depending on the vehicle, it can involve:
Some newer vehicles also require "all keys lost" jobs to go through additional security handshakes or, occasionally, dealer-level systems that a mobile locksmith may not be equipped to bypass. This is one reason the first step is always identifying your specific year, make, and model before anyone can say what's involved.
Because "all keys lost" service effectively creates a new working key for a vehicle, legitimate locksmiths verify that you're actually authorized to have one made. This protects you as much as anyone — it's the same reason you wouldn't want just anyone able to walk up and get a new key cut for your car.
Typically, you'll be asked to show one or more of the following:
If the vehicle isn't registered in your name — for example, it's a company car, a family member's car, or a recently purchased vehicle where paperwork hasn't transferred yet — call ahead and explain the situation. Additional documentation (like a bill of sale, a letter of authorization, or fleet paperwork) may be needed. This verification step is standard practice and isn't something a reputable locksmith will skip, even under time pressure.
Once ownership is confirmed, the mobile locksmith works through a sequence that generally looks like this:
1. Vehicle identification. The locksmith checks the VIN (visible through the windshield or on the door jamb sticker) and the key system used by that specific trim and year. The same model name can use different key technology across model years, so this step matters more than people expect.
2. Sourcing the correct key blank. Basic keys, transponder keys, and proximity/smart "fobs" all use different blanks and internal chips. The locksmith needs one that matches your vehicle's specific requirements — not just any blank that looks similar.
3. Cutting the key (if mechanical). If your car still has a physical key blade (many do, even alongside a push-button start), the lock cylinder is decoded so the new key is cut to the correct pattern. On vehicles with door locks that are worn or damaged, this step can take longer.
4. Programming the key. The new key is programmed to the vehicle's immobilizer or security system, usually via the OBD-II port, so the onboard computer recognizes it as authorized. On some vehicles this is a fairly quick process; on others, it requires more time, specialized equipment, or in rare cases, coordination with dealer resources for a specific security module.
5. Testing. The locksmith confirms the key locks and unlocks the doors (if applicable) and, most importantly, starts and runs the engine — not just that the engine turns over.
Every step depends on the vehicle in front of the locksmith, which is why timelines and pricing are never fixed numbers quoted over the phone before the vehicle is identified.
There's no single answer to "how long will this take," and any locksmith who gives you a firm number before seeing your vehicle is guessing. What actually affects timing includes:
The only reliable way to get a timing estimate is to call and describe your exact vehicle (year, make, model, and trim if known) so the locksmith can tell you what's realistic for that specific car. Timing is always confirmed by phone, not promised in advance or in general marketing material.
Because "all keys lost" jobs vary so much by vehicle, published price lists that ignore your specific car aren't meaningful. That said, here are the general factors that move cost up or down, along with broad, non-binding ranges people commonly encounter in the San Jose/South Bay area:
As a rough frame of reference, all-keys-lost jobs on mainstream vehicles commonly fall somewhere in the low hundreds of dollars, while proximity/smart-key systems and less common vehicles can run higher — but this varies by vehicle and key type, and the only accurate number is a quote based on your actual car. Ask for that quote over the phone once you've identified your vehicle's year, make, and model, and confirm whether it includes the service call, the key/fob part, and programming, or whether those are itemized separately.
If you're already down to zero working keys, it's worth thinking about whether to have a second key made at the same time rather than only replacing one.
Reasons to consider it:
Reasons you might not:
There's no universally "right" answer — it depends on your budget and how likely you think a repeat lockout is. If you do decide to wait, ask the locksmith whether returning later for a second key would require the vehicle to go through the full identification process again, since that affects whether waiting actually saves money.
Losing every key at once is stressful enough that most people want to avoid a second round. A few practical habits help:
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Can a mobile locksmith really make a car key without any original key?
Yes — this is the core of "all keys lost" service. The locksmith identifies your vehicle's specific key system, sources a matching blank or fob, cuts it if the vehicle uses a mechanical blade, and programs it directly into your car's immobilizer system, typically through the OBD-II port. The process differs by vehicle, so the first step is always confirming your exact year, make, and model.
Do I need the title to prove I own the car, or is registration enough?
Current vehicle registration or proof of insurance matching your name, along with a government-issued photo ID, is generally sufficient — the title itself usually isn't required for this. If the vehicle isn't registered in your name yet, call ahead so the locksmith can tell you what alternative documentation would work.
How much does it cost to replace all lost car keys?
It varies by vehicle and key type, so there's no fixed number that applies to every car. Basic transponder keys tend to fall toward the lower end of typical ranges, while proximity or smart-key fobs generally cost more due to the part itself and additional programming steps. Ask for a quote by phone once you can describe your vehicle's year, make, and model.
How long does it take to get a new car key made with none left?
It depends on your vehicle's key technology, lock condition, and part availability, so there's no universal timeframe. Some jobs are relatively quick, while others — especially less common vehicles or ones needing sourced parts — take longer. Timing is always confirmed by phone after the locksmith knows your specific vehicle.
Can a locksmith come to my house or workplace in San Jose to make the key, or do I need to go somewhere?
Mobile automotive locksmith service is generally designed to come to your vehicle's location, whether that's your home, workplace, or another spot in the San Jose/South Bay area. Having reasonable access to the vehicle (not blocked in, reachable in a garage) helps the job go smoothly once the locksmith arrives.
Is it cheaper to get two keys made instead of just one when starting from zero?
Often, yes, in the sense that adding a second key during the same visit avoids paying for a separate service call and vehicle identification process later. Whether it's worth it depends on your budget right now and how likely you think you are to need a spare soon — ask the locksmith to break down the incremental cost of a second key before deciding.
What if my key situation involves a stolen car, not just lost keys?
Mention this clearly when you call, since it may affect what documentation is needed and whether reprogramming the vehicle's security system (so old keys no longer work) is something worth discussing, separate from simply cutting a new key. This is a conversation to have directly with the locksmith based on your situation.
Can any locksmith do this, or does it need to be a dealer?
Many all-keys-lost jobs can be handled by a properly equipped mobile automotive locksmith without a dealer visit, particularly for common makes and models. Some newer or less common vehicles have security systems that may require dealer-level resources, which is something the locksmith can tell you once your vehicle is identified.
Last updated: August 2026.
