In OMICS today, buying groups work by crediting a distributor account at the end of the month, and debiting (with one big transaction) the buying group (or bill-to) account with an invoice. This is done automatically as part of the monthend and there is no opportunity for the lab to review before the credits and debits are created. Optionally, a discount is calculated on the purchases and applied to the buying group as well. The ordering ECP sees the original (full) amount of each invoice on their statement; the buying group sees the total discount that is calculated.
This allows printing a statement for the original customer, showing their purchases, but without any detail on the buying group statement at all.