REUTERS/Jim Urquhart When bitcoin first emerged banks didn't want anything to do with it. But a few years down the line and pretty much all of them are looking at it.

Although no British High Street banks currently accept bitcoin — Barclays is tipped to become the first — many of them are experimenting to varying degrees with the record-keeping technology that underpins it, the blockchain.

Earlier this month 9 leading banks formed a partnership, headed by startup R3, to create a common "fabric" of blockchain for mainstream banking — essentially establishing the ground rules.

The blockchain software works like a distributed ledger, recording and enabling transactions. It essentially eliminates the need for a trusted middleman to sit in between an exchange, as the software itself acts as the trusted middleman.

This has the potential to make transactions quicker, cheaper, and easier than currently possible, and also has potential applications for things like issuing shares.

Check out what the banks are up to, ranked from least to most advanced on bitcoin and blockchain adoption.