What's the difference between a setup and a fret job?

These get lumped together constantly because they're often done at the same time, but they're solving genuinely different problems, and you can absolutely need one without the other.

A setup

Adjusts the guitar's existing hardware to optimize playability: truss rod relief, action at the nut and saddle, intonation, sometimes nut slot depth. Nothing about the frets themselves changes. If your frets are in good condition and your guitar just needs to be dialed in properly, a setup alone gets you there.

A fret job

Addresses the condition of the frets themselves — leveling out wear and inconsistency, or in a full refret, replacing them entirely. This is a repair to the frets, not an adjustment of the guitar's overall configuration.

Why they're often bundled

Here's the overlap: after a fret level or refret, the guitar needs to be set up again anyway, because the fret work changes the surface the action and relief are measured against. So a lot of shops (mine included) bundle a setup into any fret work as standard practice, not as an upsell — it's simply necessary to finish the job properly.

When you need one but not the other

If your frets are fine and your guitar just plays poorly — high action, buzzing evenly, bad intonation — that's a setup problem. If your frets are worn, causing buzz at specific spots no matter how the action is adjusted, that's a fret problem that a setup alone won't solve, no matter how skillfully it's done.

The takeaway

Don't assume "setup" covers fret condition, and don't assume a fret job automatically includes dialing in everything else — though a competent shop will handle both together when both are needed, since leaving one out defeats the purpose of doing the other.