name on BRP card

[lolruchan]

hi, I'm in the UK on Spouse visa, I got visa and BRP card but I didn't change my name to my husband's surname.
so i still have got my maiden name on my passport,and BRP card. but the other day when I renewaled my passport, I found out that i can put my husband's surname in braket like "Emily Smith (Williams)" so I did it so on my new passport, its got his name in braket like that. in this case do i need to change my name on BRP card too like my passport?
or only when i changed my name to his properly?
I read that i have to inform BRB once my name got changed, but i didnt change my name, so im confused. thanks for your time.

[lolruchan]

additional info: Japanese authorities allow to put non-japanese family name on your passport so if you are japanese and married to non-japanese, and didnt change your name, you can put your non-japanese husband's name in bracket just to show.
so, I didn't "CHANGE" my name at all. that is why i have been confused. because on UKVA website it says i have to inform them if name had changed but i didnt.