I am in the UK, we have potential venders who have ISO27001 Certificates issued through organisations which are UKAS Accredited.
We also have potential suppliers who have ISO27001 Certificates issues through organisations which are ASCB Accredited.
I understand UKAS are appointed as the UK's "national" accreditation body but does this mean that the ASCB issued certifications are any lesser?
All accreditation bodies need to be compliant with ISO 17011, the standard which defines the process of accreditation, so there is no such thing as a lesser certification. It is more a question of market preference or legal requirement (e.g., a law, regulation, or contract may require a specific accreditation body).