Solution to mismatching zip codes?

[AmeliaNewsam]

I'm having difficulties joining a table of zip code data to the Census Bureau's shapefile (tl_2019_us_zcta510).  The shapefile has over 33,000 polygons, whereas my client's data contains roughly 24,000, and even then, about 20% of his zip codes are not included in the shapefile.  I realize that this is not technically a software problem, and zip codes are changing all the time, but I'm just wondering if anyone has come up with a creative way to solve this problem.  Are there any apps to match older zip codes with new ones... ?

[JoeBorgione]

Can you get older versions of the zip data?  Instead of only looking at 2019 data, see if Census has a archives available. 

[AmeliaNewsam]

I'll contact the Census bureau to see if they have older version, but not terribly hopeful.  But it's worth a shot.  

Thanks!

[JoshuaBixby]

So, you are working with new ZCTA data:

Census Bureau's shapefile (tl_2019_us_zcta510).

This statement seems reasonable, i.e., there are more possible zip codes than what your client has collected.

The shapefile has over 33,000 polygons, whereas my client's data contains roughly 24,000

This statement seems off to me:

about 20% of his zip codes are not included in the shapefile

Are you trying to match on 5-digit codes or 5+4 digit codes?

[AmeliaNewsam]

5-digit codes. 

[RandyBurton]

Perhaps this ZIP Code to ZCTA Crosswalk may be of help. And this page explains a bit about zip codes vs ZCTA.

[AmeliaNewsam]

Very cool, thanks!