I only use credit cards and this credit card holder from River Island is one of the best things I have ever bought. It's a 5 card slot and only cost £5:
http://www.riverisland.com/men/accessories/wallets/Brown-branded-cardholder-282918
Extremely slim and I always keep it in my front jeans pocket, so need to worry about pickpockets when out and about in central London!
http://www.riverisland.com/men/accessories/wallets/Brown-branded-cardholder-282918
Extremely slim and I always keep it in my front jeans pocket, so need to worry about pickpockets when out and about in central London!