At checkout you may get an "In Stock (Transfer Required)" notification next to an item under the Order Review section. For example:
This means that an item is in stock at our store but not our warehouse, and needs to be transferred from the store to our warehouse for shipment (or vice versa if you are collecting in store.)
This may add 1-2 business days onto your orders dispatch time. However, we are usually able to transfer items between our store and warehouse within the next business day to dispatch your order as soon as possible.
We suggest that you place these items on a separate order, as we only ever ship orders once all items are available, to avoid delays in dispatch.