Error 10018 — Main category must be Event Tickets

To add an Event Tickets category as the second category, main category must be an Event Tickets category.

Every eBay listing must be in a valid leaf category — not a parent or deprecated category. eBay periodically retires categories, so old listings or templates may reference IDs that no longer exist.

1. Look up your product's leaf category at eBay → Seller Hub → Listing Tools → Category Lookup.
2. Use the GetCategories API call (Trading API) or the Sell Catalog API to validate category IDs programmatically.
3. Don't list at the parent level — eBay redirects buyers to the leaf category and may block parent-level listings.
4. If the category was deprecated, eBay's listing tool will suggest a successor — use that instead.

• Hardcoded category IDs in feed templates — refresh from eBay's current taxonomy quarterly
• Cross-listing the same product to the same category in multiple sites (US, UK, AU) — each has different IDs