only you, your treatment provider and your alters can say whether it is necessary for you and your alters to tell your treatment provider anything about you and your alters.

each treatment provider I saw/see has their own rules and boundaries, some did require me and my alters to differentiate between each other and others did not.

let me show you something....

my talking with a treatment provider.

me...yea everything is going great , Im settling in to my new job location.
therapist... Have you had any more problems with co worker xyz? (this triggers a switch into an alter)
Alter oh yea hes a creep for sure, he did this that and the other thing and I told him if he didnt leave me alone ...
therapist ---- wait a minute I thought you just told me everything is going great and you are settling into your new job?
Alter... no I didnt Im still working at the tasty freeze.
Therapist ... ok I must be missing something here I thought you just got a job with Mcdonalds (this triggers a switch into the alter that works at mcdonalds
Alter... oh yea I do. and man the burgers sizzle on that grill. did you know that....

by now the therapist is totally confused and wondering whether client is having a psychotic break down, schizophrenic or totally manic with about 3-4 part time jobs.

now take the same situation with everyone identifying their self

me...yea everything is going great , Im settling in to my new job location.
therapist... Have you had any more problems with co worker xyz? (this triggers a switch into an alter)
Alter oh yea hes a creep for sure, he did this that and the other thing and I told him if he didnt leave me alone ...
therapist and you are?
Alter... oh I forgot to say my name didnt I sorry its Alexandra
therapist ... hi alexandra do you think there might have been a better way to handle this situation instead punching the guy?
Alex... yea but it was more satisfying lol I dont put up with it like Terry does.
Terry... yea I dont like to start trouble, Terry here by the way
Therapist... hi Terry now you work at the Tasty Freeze right?
Terry yea the benefits are horrid but the food is great. Unlike Mcdonalds.
Alter... og give me a break theres nothing wrong with mcdonalds, Pat here.
Therapist ... Hi Pat whats your favorite meal at Mcdonalds
Pat... i like the cheeseburger kids meal you get a toy with that.

this is why some of my treatment providers set the rule of identifying one self sometimes. Saves a lot of confusion and being able to follow the conversation with out jumping to conclusions that maybe the client is having a psychotic breakdown or something.