Registered & Correspondence Overseas Addresses?

Is it possible for either the company’s registered address or company’s correspondence address in the API to be an overseas address?

For “standard” UK companies there must be a UK address registered - see the rules here:

However the Companies House dataset actually includes a wider range of entities and so you will indeed find some overseas addresses. The following cases are relevant - I can’t guarantee they are exhaustive though (you can explore these easily by using Advanced Companies Search and changing the company type):

You might expect that what used to be EEIG and SE companies (now renamed) would have e.g. European addresses but the ones I have seen all have UK addresses. However in a couple of cases someone has added a different country name (presumably where they relate to) giving an odd address which is clearly in the UK (including postcode) but with a different country (Spain in my example) e.g.: HCC SHARED SERVICES, A.E.I.E. overview - Find and update company information - GOV.UK

As well as exploring in advanced search you can see this in the Companies House bulk data.

(Note: “Correspondence address” is the same field as “Registered Office” and I believe that is only for Overseas Entities.)