My birth certificate has my old name crossed out and replaced because my mum hated the way my dad pronounced it with his accent. The change is legally acceptable
The child's first words were, "Oh rah dah en dahp ooh rah daht endaht en dik ah poo ra ta teek a poo rah doo rah do dik oh mumblio dah dah dosa pa errah sa dey definitely ha to think about pa errah so ma et it heh uh uh rah nada no ob rah da sa oh rak ah you ma heh to bro rah de de eh ah is ah ra ray nah hear aned darayeah woo who rah eh pay pa do rah not to errraah!"
I was thinking the same thing. I'm pretty sure you need to sign the documentation after double checking what the registrar has put down. We have up to 6 weeks too to register the birth if you haven't had chance to decide on a name yet.