Quick Summary:
- Enter the plate exactly as printed, usually without spaces or dashes.
- Select the issuing state on screen, California unless your hire car is out-of-state.
- For temporary tags, type the temp number and photograph the tag.
- Keep screenshots of the confirmation and payment details in case ANPR misreads.
Pay-by-plate parking in San Francisco is designed to be simple, but it can feel stressful in a car hire vehicle because you did not choose the plate and you might not know its exact format. The key is to treat the plate entry like a data entry task: copy what the vehicle displays, choose the correct state, and create a small evidence pack so you can respond quickly if a camera or enforcement system reads it differently.
This guide focuses on practical steps you can do at the machine or in the app-style terminal, with special attention to plate formats (spaces, dashes, zero vs O), temporary tags, and what to save on your phone. If you are collecting a vehicle via car rental at San Francisco SFO you can do a quick plate check in the car park before you even drive off, which makes the first pay-by-plate stop much easier.
Before you start: identify what plate you are meant to enter
Most pay-by-plate systems in California expect the front or rear registration number currently displayed on the vehicle. In a car hire car, confirm which identifier is being used:
1) Rear metal plate. For most cars, this is the correct one to enter. Copy the characters only, not the state name or slogans.
2) Front metal plate. California vehicles normally have a front plate, but some out-of-state vehicles may not. If the front and rear differ (rare), use the plate associated with the vehicle registration, typically the rear plate.
3) Temporary tag. If the vehicle has paper tags in the rear window or where the plate would be, the temporary number is usually what the system needs. Some tags also show a small plate-like code plus other numbers, so you must pick the actual tag number.
4) Barcode or fleet number. Ignore internal stickers, windscreen barcodes, or car hire fleet identifiers. Pay-by-plate is based on the public registration identifier that enforcement can observe.
If you hired a larger vehicle, such as via minivan hire in San Francisco SFO, plates can be harder to read due to plate frames, tinted covers, or dirt. Take a clear photo immediately and zoom in when typing at the machine.
Checklist: entering the plate characters correctly
Use this checklist at the machine to reduce common entry errors that trigger ANPR mismatches later.
Copy characters exactly, but usually remove separators. Many pay-by-plate machines ignore spaces and dashes, or they do not allow them at all. If the plate is shown as “7ABC123”, enter 7ABC123. If it appears visually separated (for example a space between groups), still type the continuous string unless the machine provides separate boxes.
Do not add “CA” or state slogans. Only enter the plate characters. The state is selected separately on most systems.
Watch for 0 versus O. Plates often include zeros, especially in the numeric section. If you are unsure, photograph the plate and zoom in. On many plates, the zero is more oval, while the letter O is rounder, but this varies.
Watch for 1 versus I, and 5 versus S. Some fonts make these easy to confuse. Double-check any ambiguous character by comparing it with another letter on the same plate if possible.
Type exactly the number of characters. If the plate has seven characters, do not add leading zeros and do not drop a character to “make it fit”. If the machine limits characters and it does not accept the full plate, cancel and start again, then check if you selected the wrong state or plate type.
Ignore plate frames that hide characters. Some frames cover the top or bottom. If any character is obscured, use your phone camera at a slight angle to read it, and photograph it in case you later need to show what you could reasonably see.
Confirm with a second source. In a car hire vehicle you can often verify the plate number on the rental agreement, key tag, or the vehicle info screen in the infotainment settings. Use this only to confirm, not to override what is physically on the vehicle if the agreement appears outdated.
Which “state” should you select on the machine?
Pay-by-plate systems frequently ask you to choose the issuing state. In San Francisco, the correct choice is the state that issued the registration shown on the plate or temporary tag, not your driving licence country, and not where you are parking.
Most of the time, choose California. A large share of car hire vehicles based around San Francisco will be registered in California. If the plate says California, select CA or California in the state list.
If the plate is from another US state, pick that state. Some fleets rotate vehicles, and you may have an out-of-state plate. Choose the state printed on the plate, for example Nevada or Arizona.
Temporary tags still have an issuing state. A temp tag normally shows the issuing state or dealership state. Select that state, then enter the temp number.
What if the machine defaults to California? Do not assume it is correct. Always confirm the state selection before paying. An incorrect state can produce a “valid payment, wrong vehicle” situation if the system treats state plus plate as the unique key.
What if you cannot find the state? Scroll carefully, some systems use abbreviations, some use full names. If the state is genuinely missing, take a photo of the state selection screen showing it is not listed, then pay using the closest supported workflow (for example, a “Other” option if provided). Do not guess a random state.
If you collected your vehicle outside the city, for example after landing at SJC using car hire at San Jose Airport SJC, it is even more important to check the plate and state before your first San Francisco parking session, because out-of-area fleets are more likely to be mixed.
Temporary tags and paper plates: what to enter and what to photograph
Temporary tags cause the most confusion because the layout is busy and the “plate number” might not look like a normal plate. When you see a paper tag:
Find the explicit plate or tag number. Look for labels such as “Plate”, “Tag”, “Reg”, or a bold alphanumeric code. Ignore VIN, stock number, dealer number, or long barcode strings unless the tag explicitly says that is the plate number.
Enter the tag number exactly as printed. Keep any hyphenation out unless the machine requires it. If the machine allows only letters and numbers, omit hyphens.
Take two photos. First, a close-up that clearly shows the tag number and issuing state. Second, a wider shot showing the tag in the vehicle window so it is obvious it belongs to that car. These photos are useful if enforcement later claims “no valid plate payment”, especially if an ANPR camera struggled with glare or tint.
Consider glare and tint. Many rear-window tags sit behind glass, which can create reflections. Step to one side and photograph at an angle so the number is readable.
Recheck each time you park. Temporary tags can curl, fade, or be partially obscured by condensation. If readability changes, update your evidence photo.
Using the machine: a step-by-step workflow that reduces mistakes
Although different vendors use different screens, the safest workflow is consistent:
1) Before touching the screen, open your camera and take a clear photo of the plate or temp tag. This prevents “I can’t remember it” moments halfway through.
2) Start the session and choose the zone exactly as posted on the sign by your space. Zone errors are as common as plate errors.
3) Select state first if the machine asks. Confirm it matches the plate.
4) Type the plate slowly, then pause and compare each character with your photo. If the machine shows a review screen, use it, and do not rush.
5) Choose duration based on the time limit and your plans. If you are unsure, pay for a shorter period and extend if the system allows, rather than selecting a long stay that might be invalid for that location.
6) Complete payment and save proof. You want proof that links three things: the plate you entered, the location or zone, and the time window paid.
7) Walk back to the car and check signage once more. If there is a separate permit restriction or street-cleaning rule, a correct pay-by-plate entry will not override it.
What screenshots and photos to keep if ANPR later misreads your plate
ANPR and plate-reading errors happen for normal reasons: glare, motion blur, a dirty plate, a plate frame, or a camera that confuses similar characters. If you get a notice later, the difference between an easy resolution and a prolonged dispute is often the evidence you kept at the time.
Keep these five items in a single album on your phone:
1) Plate photo showing the full plate and state. For temp tags, make sure the tag number is legible.
2) Machine confirmation screen screenshot or photo that shows the plate you entered. If you cannot screenshot, photograph the screen clearly.
3) Receipt photo. Many machines print a receipt or show a receipt code. Photograph the paper receipt next to the car’s plate, if practical, to tie it to the vehicle.
4) Zone and sign photo showing the zone number, hours, and any restrictions. This proves you used the correct location data.
5) Timestamp context. Take one wider photo showing your car parked near the sign or pay station. Your phone’s metadata will store date and time, which helps establish you paid before enforcement.
Tip for character disputes: if ANPR read “8” instead of “B”, your plate photo plus the confirmation screen showing what you typed can demonstrate a reasonable entry and identify the likely misread. Keep everything until well after your trip ends and any payment issues are resolved.
Common edge cases for car hire vehicles in San Francisco
Plate frames with branding. Some car hire companies use frames that slightly cover a character. Photograph the plate and consider gently wiping dust off the plate surface with a dry cloth so cameras read it better.
Vehicle swap during your trip. If your vehicle is replaced, your plate changes. Update any saved parking app profiles and be cautious with “repeat last session” features at machines.
International driving habits. UK visitors sometimes look for a “registration document number” rather than the plate itself. In San Francisco pay-by-plate, it is the displayed registration identifier that matters.
Multiple plates saved in your phone. If you travel with companions, label your photos with the car make and colour so you do not type a different vehicle’s plate by accident.
Parking after airport pickup. If you drove in from SFO using Enterprise car rental at San Francisco SFO or another provider, your first city parking stop can be hectic. Pull over safely first, photograph the plate, and then approach the machine with the information ready.
What to do if you realise you entered the wrong plate
If you spot the error immediately, act quickly:
Cancel and re-pay if possible. Some machines allow cancellation before final confirmation. If not, pay again with the correct plate and keep both receipts and screenshots.
Document the mistake. Photograph the incorrect confirmation screen and then the corrected one. This can show good faith if you later need to explain duplicate or mismatched payments.
Do not edit photos. Keep originals so timestamps and metadata remain intact.
Tell the driver group. If multiple people share driving duties, message the correct plate format so the next parker does not repeat the error.
FAQ
Do I enter spaces or dashes from the number plate at San Francisco pay-by-plate machines? Usually you should enter the characters continuously, without spaces or dashes, unless the machine provides separate boxes or explicitly requires punctuation.
Which state should I choose if I am in a California car hire vehicle? Select the state that issued the plate shown on the car, most commonly California. Do not select your home country or the state you are visiting.
What if my car hire vehicle has a temporary paper tag instead of a metal plate? Enter the temporary tag number exactly as printed and select the issuing state shown on the tag. Photograph the tag close-up and in-context in the window.
What proof should I keep in case ANPR misreads my plate? Save a plate photo, the payment confirmation screen, the receipt, and a photo of the zone sign. Together they show what you entered, where, and when.
Can I rely on the rental agreement plate number rather than the physical plate? Use the physical plate or tag as the primary source, then cross-check with the agreement for confidence. If they conflict, photograph both and enter the number displayed on the vehicle.
