Director identification

Is there any way within the API to uniquely identify directors across multiple companies?

Ie search for a Director by a unique ID number and return all companies they have current or past associations with - rather than search for “John Smith” and potentially get a number of different people with the same name

There is an officer appointment list call:

Ah thank you Id missed that method, but is there anywhere I can retrieve a directorID from that you need to feed that call? As the company officer list doesn’t seem to have any return field for directorID

It’s the long string in the middle of the links:officer:appointments element.

Not sure how comprehensive or reliable the appointment list is though. When you appoint someone you don’t tell CH if they are the same as an existing person, so they must match them based on some elements of that person’s identity. Probably a few John Smiths born on any given day, so guessing address must be part of that process as well.

As @ash says (multiple John Smiths) plus your particular John Smith might be represented by more than one ID. I think there may be different IDs for different combinations of name / age / address.

Examples (BTW I don’t have proof that any of the following are identical but I’m pretty sure! You be the judge):

(These two have the same name, age and address but the addresses differ by a comma).

Dominic Joseph Andrew CHAPPELL Born November 1966. There are several different IDs, and possibly one under Dominic CHAPPELL Born November 1966. Try searching Dominic CHAPPELL).

The scope / consistency of officer IDs seems to be a serially unanswered question.
An example with useful analysis:

It’s the same but more so with PSC IDs (if you’re interested in those) - they don’t seem to be transferrable anywhere: