So sorry to resurrect this thread, but please be careful when letting yr DC take on another surname without legal paperwork.
My sister and myself both 'took on' my step father's surname, although it was never ever legal, and when our NI cards came through, they came through with our assumed surname (step father's surname, which I'll call B to help me come across clearly).
This has caused me untold problems over the years, since all my NI, tax and benefits are now under the name on my NI card, ie: step father's name, yet my birth certificate is still in my mother's maiden name, which I'll call A to clarify.
Just as an example, I cannot study OU, since I cannot prove that the person on my birth certificate (Miss A)is the same person on my NI card or the same person who is in receipt of benefits,(Miss B) for financial support.
I also opened a bank account to have my benefit paid into, and was helped to buy a car. I used this bank account, in the name of Miss B, to pay for the car, so my car is now legally owned and registered to Miss B, yet my driving licence is in the name of Miss A. This causes me untold angst when insuring my car.
I have never legally been Miss B, yet because NI were informed by my school that I was indeed Miss B, that is why they sent my NI card in name of Miss B.
Anything that involves sending off my birth certificate requires me to name myself as Miss A, and anything that involves work or benefits requires me to call myself Miss B.
And it's such a pita when the two are required at the same time. I have been quizzed incessantly over the phone and to my face as to why I have 2 different surnames, yet have never been married or divorced. Commonly asked whether Miss A is my maiden name, and trying to explain to people is frustrating.
My sister married and so has changed everything to her married name, without too much explanation, but I am tired of explaining that my mother decided to call me after my step father. I have also been told by benefits agency that they can revert me back to Miss A, but this would involve going back at least 24 years in my records, (which they are not sure are actually available any longer after so much time) to verify that Miss A did indeed disappear without passing away, only to be replaced by a Miss B who was never born. I then need to prove (although they can't tell me exactly how I can do this) that the 2 people are one and the same.
It has been a living nightmare tbh, and this is why I made a concious decision to never ever change my DC surname, no matter what, unless it was accompanied by legal documentation as proof that they were indeed formally known as .
I have also phoned NI, who aren't in the slightest bit interested in my dilemma and will only say that NI numbers are generated upon the child's birth being registered, and so they cannot explain why I now have a NI card and tax records in a different name.
I find I open a mammoth can of worms every time I try to explain.
HTH prevent even just one more person from living their life under almost constant scrutiny over their name or assumed name.
Please Please always let schools and drs, dentists, govt people know yr child's legal name.
That's all.