With version 1.4.0.14 and newer, the accounts tab is hidden when "Hide account codes" is used.
To view or edit account codes,
click on "[Setup -> Properties -> Filters and Defaults]".
Uncheck the "Hide account codes" checkbox and click on apply.
You need to restart Topaz before the account codes tab will become visible.
Make any necessary changes,
and then check the "Hide account codes" checkbox again.
When Topaz is restarted, the account codes tab will be hidden again.