Each time we do spell checking it is defaulting to the US dictionary. Is there a setting in the .ini file for inmagic or the individual textbase where the dictionary can be set to default to british spelling?

You can remove the American English dictionary completely by running Setup Workstation, and unchecking it on the Select Spell Check Dictionaries dialog box.

Or, you can do the same thing by manually editing your registry as described in Knowledgebase article 2086: "How do I change my dictionary from American to British (or another dictionary) ?"