Bit of back story - myself and partner been together 3.5 years and we are getting married in May 2021 so we will be together 5 years when married. My partner has been like a dad to my 6 year old son with special needs. He comes to all hospital appointments, speech and language and OT sessions, school meetings ect. He pays for days out for my son, teaches him to play football, helps me with parenting, looks after him when im at work (we live together). His dad on the other hand sees him once or twice a month, doesn't ring him/facetime or ask about him inbetween visits, cancels seeing him for less important events (nights out), he pays for him weekly but after a lot of hassle and arguing first. Says I dont need his money I get enough from child benefit (what a joke). He's on the birth certificate and my son has his last name.
My question is once myself and partner are married do we need birth dads permission to double barrel last name?
So it will be first name then partners surname then birth dads surname.
Hope that makes sense..
(I've given back story so you know the reason for wanting to change surname)