Balance transfer fails when sending to the AccountIndex

Question

I wanted to try out AccountIndex feature on Westend: https://wiki.polkadot.network/docs/learn-accounts#indices and claimed an index: https://westend.subscan.io/extrinsic/11590551-2

When I try to do balance transfer using the Account Index on Polkadot-JS Apps UI, the transaction fails. Any idea why this is happening?

Answer 1

This is not supported on-chain:

• https://github.com/paritytech/polkadot/blob/fb2c9ae0eece5a79356f7e7271cf3232f0143b0c/runtime/westend/src/lib.rs#L155

You always need to do the id lookup off-chain.

The second parameter of AccountIdLookup is the id which is set to () aka "nothing".

This was done to make the benchmarking predictable. Otherwise the worst case of each extrinsic would include the lookup of the ID to accountId.

Thanks Basti for this answer.