The way OLX currently works (or perhaps I should say "doesn't work") is illustrated by the following example:

Scenario 1
1. The Raiser's Edge has the zip code of 12345-1234. 

2. The donor enters their zip code as 12345.

Online Express is able to match on the zip code using just the first 5 digits

Scenario 2
1. The Raiser's Edge has the zip code of 12345.

2. The donor enters their zip code as 12345-1234.

Online Express is not able to match on the zip code with the +4 at the end.

The developers should fix this so that OLX can match in the latter scenario.