It is often possible to perform foreign transfers using destination IBANs, but they seem to prefer (or require) the traditional approach for UK Sterling transfers.

I can understand why they retain the old system, but it would be useful if they in addition offered the ability to specify the target via IBAN for domestic transfers, since they already do for transfers to the rest of the EU.

Even when doing a SWIFT transfer, the IBAN (if one has it) is useful.

Japan has the same system of sort/branch codes and account number, but when I enter those here the recipient name is automatically filled out, making incorrect transfers pretty much impossible (unless, I guess, your mis-entered transfer to Mr. Sato is transferred to a different Mr. Sato instead)

A part of the Eurozone transition was that all local systems were replaced by SEPA SCT/SDD, which are inherently IBAN based. But SCT/SDD only apply to Euro transfers, and so in non-eurozone locales the existing infrastructure and nomenclature is retained

> Japan has the same system of sort/branch codes and account number, but when I enter those here the recipient name is automatically filled out, making incorrect transfers pretty much impossible (unless, I guess, your mis-entered transfer to Mr. Sato is transferred to a different Mr. Sato instead)

There is a Confirmation of Payee system coming soon in the UK (which most of the large banks have, unfortunately, delayed). It works slightly differently: it will compare the name, but not _generally_ tell you the name of the recipient because that comes with privacy concerns

These could be compatible though. e.g. in Poland numbers used for local bank transfers are just IBANs with country code trimmed from the front.