Generally retailers don't award cashback if the item is reserved and paid for later, reserved and paid for in store or saved in your basket.
This is because cashback is a referral commission paid to Quidco for referring you to make a purchase, so if the retailer can't see that you went straight from Quidco to make your purchase with them, sometimes cashback may be declined.
We would always advise starting a new shop from Quidco and following it all the way to payment stage in the same sitting to give you the best chance of receiving your cashback.
Updated over a week ago