To enter a foreign address in TaxAct®:
Per IRS Instructions for Form 1040, page 13:
If you have a foreign address, enter the city name on the appropriate line. Don't enter any other information on that line, but also complete the spaces below that line. Don't abbreviate the country name. Follow the country's practice for entering the postal code and the name of the province, county, or state.
While the IRS instructions above state to not abbreviate the country name, the IRS provided the following specific instructions to all software developers in September of 2013:
ALL formats should be standardized to be the 2 digit country code provided by ISO. The 2 digit should be used in both print and EF.
The TaxAct programs select country codes according to the Foreign Country Code Listing for Modernized e-File (MeF) which is what software developers must follow.