I need to find a way to identify ZIP Code ranges for selected cities
and counties in California. For example, what are the ZIP Codes in Los
Angeles County. I am willing to buy appropriate softare or use a
research service.

Hello kingpickle:

Thanks for the interesting question. 

The research I have done so far seems to indicate that you may not
need to purchase any further software/service to get what you want. Of
course, that all depends on whether I have completely understood your
needs. :-)


What I've been able to find for you so far is:

1. A list of zipcodes for California sorted by city. 

555CA -- California ZIP Codes
URL: http://www.555us.com/555CA/555ca_zipcodes.htm

The data is sorted on this page both numerically (by zipcode) and
alphabetically (by city name). All you need do is scroll down to the
city you want and read off the zipcodes. I found several sites with
identical types of city-based information.

2. A list of zipcode ranges for counties in California.

California County Zip Codes Breakdown
URL: http://www.chinesemailing.com/english/mailinglists-cazipcodebreakdown.htm

As you can see the zipcodes for each county are not necessarily
contiguous.


IF you want further information (e.g., area codes to match, longitude,
latitude, etc.), I suggest purchasing a data product such as:

ZIPCodeWorld™ United States Premium Edition
URL: http://www.zipcodeworld.com/zipcodepremium.htm

This data comes in several formats, including spreadsheets which would
be easy to sort however you wanted.


I hope this information helps with your research.                    
                    
If you need any clarification of the information I have provided,
please ask using the clarification feature and provide me with
additional details as to what you are looking for. As well, please
allow me to provide you with clarification(s) *before* you rate this
answer.
                    
Thank you.                     
                    
websearcher-ga                     
                    
                    
Search Strategy (on Google):                     
 
california zipcodes 
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california counties alameda colusa zipcodes 
california county  zip codes 
california counties

Good and prompt answer.

Dear Kingpickle,

The United States Postal Service has a ZIP Code Lookup at:

http://www.usps.com/zip4/

You can probably find what you need using the "All ZIP Codes for
City/Town" option, at:

http://www.usps.com/zip4/citytown_zip.htm

I trust this helps.

Carnegie