Hi Johnny Gorman Thanks for posting your query on Microsoft Q&A.
As shared by Arun above, your understanding is correct.
UK West region doesn't have availability zone currently but UK West does have datacenter. Each Azure region features datacenters deployed within a latency-defined perimeter.
Azure availability zones are physically separate locations within each Azure region. Azure has availability zones in every country in which Azure operates a datacenter region. For now, UK has availability zone available in UK South region only (and not UK West).
But Azure is rapidly opening new regions and availability zones. Any new updates will be added here.
Azure regions are designed to offer protection against local disasters with availability zones. But they can also provide protection from regional or large geography disasters with disaster recovery by making use of another region that uses cross-region replication. UK South and UK West are regional pairs to each other, if that helps make a decision.
For more information, see :
If you have any questions at all or need further clarity, please let us know in the 'comments'.
If any of the answers here helped, please consider accepting the answer so that it can improve discoverability for others in the community looking for help on the same topic.