There is room on your license, I believe for both your po box and your street address. There is an extra line provided when you change or apply.
The other thing to do is put it all on one line:
1234 Pine, PO Box 670
What about licenses that don't have the current address printed on them? The DMV is well aware of where to send the vehicle license renewal notices, and I've filed the appropriate form to change my license address (or so I thought), but the license itself doesn't expire until May 2008.
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From the CA DMV website:
How to notify DMV when I change my address
Law states that you must notify DMV within 10 days of changing your address. There is no charge to change your address, and you may notify DMV by any of the following ways:
1. Complete your change of address online.
2. Call any DMV office at 1 (800) 777-0133 and request that a change of address form be mailed to you. It will take 5 days for you to receive it. Complete the information required on the form, then mail it to the address listed at the top of the form.
3. Download the Change of Address form DMV 14, complete the information, and mail it to the address listed at the top of the form.
4. Visit any DMV office, complete a change of address form, and give it to a technician. The technician will give you a Change of Address Certificate card (DL 43) to complete and carry with your license.
If you do 2 or 3 above, type or write in ink your new address on a small piece of paper, sign and date it. Carry this piece of paper with your license. Do not tape or staple the change of address information to your driver license.
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There is also a place on the back of my current license to write the current address. I've written both street address and P.O. Box in the appropriate area.
I checked another portion of the DMV website to see if they had my current address. Apparently they do not, and I submitted a change of address form electronically. It takes three business days for the new address to propagate into the DMV system, so I'll check it again next week to see if it made it through.
If interested in checking your own information, here is that website:
http://www.dmv.ca.gov/online/coa/welcome.htmYou have to go through a couple of layers of information before you actually get to the page that allows you to either CHECK your address, or INPUT a new one.
Peace