Zipcode vs Zipcode+4: Does Zipcode+4 provide more granular encoding?

[JackBoyd]

I have a table of incidents with counties and zipcodes.  Half of the records have zipcode+4 data. If I encode this table in ArcGISOnline, does the geocoding process treat zipcode+4 data as more granular than zipcode only?  Or should I just encode the records with zipcode?   I will eventually be aggregating to a block level so I can do drive time analysis of 'incidents in Business Analyst so the more accurate the geo-coded data the better.  Thanks. 

[ShanaBritt · Accepted solution]

Jack:

Zip+4 is more granular than just 5 digit zip code. The additional 4 digit extension to the zip code represents a delivery area, a city block, a group of appartments, or PO Box for example within a 5 digit zip code region. If you are using the ArcGIS World Geocoding Service it allows you to include the zip code extension, which must be in a separate field from the 5 digit zip code. 

[JackBoyd]

Thanks,  Shana.  When I have imported data at the zipcode level, I have aggregated the data using ArcGIS 'Aggregation' function using a ;zipcode' boundary to create a map layer that can be used in other Business Analyst analysis.  If I now use Zip and Zip+4 data, I assume I should aggregate the imported data down to block level, right?  So i don't loose the additional granularity?  Thanks for the assist.