Preflight

Before a product publishes to a channel, CellerHub checks everything that channel would refuse on — using the exact same check the publish itself uses. If preflight says a channel is ready, publishing won’t fail for a reason preflight could have caught.

Nothing here costs a call to the channel — every check runs locally against what you’ve already entered, so the product page can ask on every render.

Setup gaps come first

If you haven’t finished setting up a channel account at all, CellerHub tells you about that before it tells you about a missing field on one product — fixing the account unblocks every product on it at once, so there’s no point sending you to fix one item first.

Common setup gaps:

What’s missing	Where to fix it
Shipping terms	Connect eBay → “Your eBay terms,” or Settings → Listing setup
Return terms	Same as above
Ship-from address	Settings → Warehouses
A first listing on Mercari	Make one directly on Mercari — see Connect Mercari

Then the product itself

Once a channel’s account-level setup is complete, preflight checks the product:

• At least one photo
• A title within the channel’s length limit
• A description
• A condition, or a condition the category accepts, or one Mercari recognises
• The package weight
• Item specifics the category requires, named individually so you know exactly which ones

Fixing a gap

Each gap preflight reports names the field it’s about and, where there’s one obvious answer, focuses that field for you directly. Fill it in, save, and preflight re-checks automatically — there’s no separate “recheck” step.

If a channel still refuses after preflight said it was ready, see When a channel refuses.