Your order contains two numbers: an SBP number and a BP number.
BP number: relates to the individual product.
SBP number: relates to the entire order.
For example, if you have ordered a landscape photo book and a mug in a single order, the number relating to the entire order would be the SBP number. The landscape book would have a BP number, and the mug would have a (different) BP number.
If you have ordered multiple items of the same product, you will only have one SBP and one BP number.
If you have purchased a voucher, please do not confuse the order numbers with your voucher number. A voucher will never begin with BP or SBP and must be downloaded from your account.