Regional & commercial

Open Settings → Business → Regional & commercial. These are facts about the business rather than preferences: the timezone schedules run on, the currency values are shown in, and how tax is read off the figures your systems supply. Owners and admins can change them; everyone in the workspace reads against them.

Control What it changes
Timezone Schedules, routines, briefing delivery and activity timestamps.
Currency The default currency for commercial values.
Country Regional formats, and the integrations that need to know where you trade.
Tax name The word Twelfth uses for tax on source amounts — GST, VAT, sales tax, or a generic label.
Preferred inventory tax basis Whether supplied stock costs are shown including or excluding that tax.
Change these before the data, not after

The tax basis and currency apply to what Twelfth shows, not to what your systems send. If the source feed reports costs including tax, say so here so a margin is read the same way everywhere.