Should Total Contract Value be represented in pence or pounds for UK Gas trade confirmations?

Should Total Contract Value be represented in pence or pounds for UK Gas trade confirmations?

The eCM Standards state in the Currency field:

"With boolean Attribute “UseFractionUnit” to indicate that “Pence” is used instead of “GBP”. This attribute becomes mandatory when issuing CNF documents for the networks that utilize pence. (i.e. UK NBP and Belgium)."

UK NBP (National Balancing Point) is a virtual trading location for the sale and purchase and exchange of UK natural gas. Gas at the NBP trades in pence per therm.

UK Gas trades should therefore be submitted to CMS using "GBP (fract.) i.e. Pence.