ShipScript has been an eBay Community volunteer since 2003, specializing in HTML, CSS, Scripts, Photos, Active Content, Technical Solutions, and online Seller Tools.
There are generally two kinds of errors.
The structural errors are immediately fatal and the file is rejected. This is often caused by line breaks inside cells (usually the description field), using Mac instead of Windows file formats, by extra spaces around headings, bad headings, or missing columns, and when the Action field is not first in the page.
Lesser errors allow the file to load for processing, but eBay can not post the listing due to erroneous or missing field data. A report will be generated with error messages that call out the bad data. Oftentimes, you may need to fix one error, and then the upload will reach the next error, and so forth as you are tediously walked through each one.
There will occasionally be warnings, which are generally just advisory. eBay will usually post the listing and may convert or omit any unnecessary data that was offered.
If you are good with Excel, the best place to start is to download a category-based listing template from Seller Hub > Reports > Uploads.
https://www.ebay.com/sh/reports/uploads
Since you are in the UK, the page would be here:
https://www.ebay.co.uk/sh/reports/uploads
If you download the XLSX version, it will have dropdown suggestions in the data cells that have particular requirements. The data should be entered left-to-right, due to some dependencies that can change the data requirements in later cells.
Some columns are not in the spreadsheet. If you use calculated shipping or eBay International Shipping (regardless of whether or not you use business policies), you will need to provide package specs. These are the columns:
PackageType (Letter, LargeEnvelope, PackageThickEnvelope)
WeightUnit ('lb' for imperial measurement)
WeightMajor (number of pounds)
WeightMinor (number of ounces)
PackageWidth (whole number)
PackageLength (whole number)
PackageDepth (whole number)
PostalCode
