My time travelling in Scotland, England, and France over the last couple years taught me that there is a lot more coin usage in the UK and EU in general than in the US (one and two pound or Euro coins instead of bills), and I use a small zipper closing change purse with a pair of pockets on either side that can hold bills and credit cards, ID, hotel room keycards, etc... all in one place. Fits nicely in the sporran (or in my case small belt pouch) and keeps all the essential together in one small package no bigger than a wallet and probably smaller than most. The hard part with a sporran is keeping the small purse on top if you are in and out of your sporran frequently for other things like cell phones, keys, etc... That is why I generally carry a small belt pouch with the most frequently used items there and other "stuff" in the sporran where it is slightly less accessible.