I am trying to find out if there is a good way to find nine digit zip codes. I work for a non-profit Soil and Water Conservation District and we would like to send out a mailer. To get the bulk mailing price we are required to use a nine digit zip code we only have a five digit code. It seems there are a lot of companies that are selling this data. The lowest price I have seen is about 300 dollars. We have about 400,000 records that need the nine digit zip code. Is there any way I can use the Address Locator to populate the nine digit zip code?