ESA change of circs

Leaving aside any issues with a partners earnings would a single claim for IR ESA be ended if the claimant tried to add a new partner to the claim? 

At first sight I would have said that this would be the cause of a natural migration to UC but if it does not cause a new claim for ESA (and is just a change of circs on an existing claim) then would it necessarily cause a UC migration

ESA is claimed by an individual who may or may not have a partner. If that individual acquires a partner, that can be dealt with within the award with no new claim required. There is no such thing as a joint claim for ESA.

thanks1