ISX Plc December Update, page-87

I think volume refers to value, the same way it is used in GPTV.

I also think a lot of the volume would be from existing clients/users moving away from card acquiring to SEPA - unless we've had some significant sign-ups since demerging. It's in line with ISX's strategy. ISX can retain more profits from SEPA, unlike card transactions which cost more to process. Merchants also won't have to deal with chargebacks and other risks associated with card payments, so it's a good trend.