Although Sage have now released updates to allow SSD reports to be produced from 2021 onwards, I've also done an add-on that will work round the problems. This can be used as a quick fix if it's inconvenient to upgrade Sage 200 at the moment.
The add-on can be freely downloaded from Intrastat_2021.sdbx and installed using System Administrator / Add-ons / Add new add-on.
This add-on comprises 5 VB scripts which alter these Sage forms, all in Accounting System Manager / Intrastat (SSD)
- Intrastat Entry Maintenance
- Intrastat Entry Maintenance / Edit View
- Intrastat Entry Maintenance / Add Entry
- Produce Draft Intrastat Declaration
- Produce Intrastat Declaration
If you want to look at the source code, it can be extracted from the .sdbx file by opening it either Sage's Add-on Packager, or a utility such as 7-Zip. This add-on should work with any version of Sage 200.
The problems were happening because the Tax Year lookup was hard-coded with years 2000-2020, so 2021 couldn't be selected. So this add-in changes the years to 2020-2025.