Can I access the Welsh Demographic Service (WDS) as an existing user of the PDS HL7 V3 API?

The Demographics team has advised:
Basically, no.
The HL7v3 API employs the message set contained in the Message Implementation Manual (MIM), which is the basis for becoming Spine Compliant using that API.
This not the same as becoming compliant to connect to the Welsh Demographic Service (WDS). I’m not sure what message set that uses, you would have to contact The Welsh about that.

To get in touch about making use of the WDS, please contact Digital Health and Care Wales (DHCW) using the information on Contact us - Digital Health and Care Wales (nhs.wales).

For general enquiries they advise:
To make a general enquiry or to give DHCW feedback about our services, you can:

We welcome contact in Welsh and English.