It may be that the items might meet one of the below criteria.
The item must have been listed, without any change to item price, postage price, title or item description, for at least 14 days before it can be included in a sale.
If a listing is already in a sale or has bids on it, you won't be able to add it to a sale.
A listing can only be in one active sale at a time, but a listing can exist in multiple scheduled and inactive sales. If the dates overlap, the listing will be in the sale that was most recently set-up.
Items can be included in a sale for a maximum of 14 days, after which it needs to be excluded from a sale for at least 14 days before it can be added to a sale again.
Revising the item price and/or postage cost for an item on the Revise my item page removes the item from a sale.
