Service zones are the areas you cover, defined by the postcodes in each one, with any trip charge that applies.
What it gives you
A zone lists the postcodes it covers and what is charged for travelling there. A postcode lookup answers the one question that comes up on every inbound call: do we go there, and what does it cost?
The value is consistency. Without zones, that answer depends on who picked up the phone and how busy they feel, which is how a business ends up sending a van ninety minutes each way for a job that could not possibly carry it.
Trip charges are a margin tool
A trip charge is not primarily revenue. It is the thing that keeps distant work from being unprofitable work.
Drive time is the cost that never appears on an invoice and is almost never quoted for. A two-hour round trip on a three-hour job is not a three-hour job — it is a five-hour job priced as three, and it will show up in job margins as an inexplicably weak result on work that seemed fine.
Reviewing the edges
The zones worth re-examining are the outer ones. Look at the margin on jobs from the furthest postcodes: if they consistently come in below the rest, the choice is to raise the trip charge, or to stop covering them and give the time back to work closer in.
Either is a decision. Continuing without looking is not.
Where they come from
Zones sync from your field service system. If nothing appears here, none have been set up there yet.