if your Sage Accounts Data Service is running on a different PC or server then you may need to open up TCP ports in order for the client program to connect. The ports to be opened are as follows:
- V21 - TCP ports 36289 and 36290
- V22 - TCP ports 42100 and 42222
- V23 - TCP ports 34223 and 32223
https://my.sage.co.uk/public/help/askarticle.aspx?articleid=32014