In the US, you can change your last name as you could with your first name. So imagine as a father, you changed your last name from the one your family gives to you. Can you choose your child to use your family's last name not your changed last name?

2 Answers 2


No law in the US requires that parent and child have the same last name. It is usual that a child's name match that of at least one parent, but not required.

A parent can change his or her name, without changing the names of any existing children. Also, when a child is adopted, the child's name need not be changed to match the name of the parents, or either of them.

I have read of cases where a widow remarries, and takes the name of her new husband, but an adolescent child retains his or her birth surname. I suppose this would also be possible legally if it is the husband who changes name on remarriage, but i have not read of such a case.

I think, but I am not sure, that a child's name could be changed to a different name than the name of either parent. It may be that this would only be done if the child is old enough to understand and agree to the change.

  • How about the name is changed before the baby born? Since I'm Dale's child said When you name your child there is a convention that they take the father’s last name but you can give them any name you like Mar 2, 2019 at 3:10
  • I suspect that the parents may agree to name the child whatever they like, but that may be a matter of state law, and i am not sure. Legally, i believe the choice of name is not effective until the child is born, and for many purposes, not until the birth certificate is filled out and filed. Decisions on a name before birth are simply plans, and do not bind anyone. Mar 2, 2019 at 3:14
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    My nephew's last name was basically a fiction for the first several years of his life. It wasn't until the mom won sole custody and changed his last name to her own that he had a last name that really "came from someone". I think his original name was some sort of weird agreement she and the father had because they weren't married, weren't really sure they would get married, etc., so they created a last name for him. I don't know why that seemed sensible to them at the time, but that's what they did. Mar 2, 2019 at 11:35
  • It is quite common when neither parent changes names upon marriage, or if the parents aren't married, for the children to have hypenated surnames.
    – ohwilleke
    Mar 6, 2019 at 6:11
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    @DavidSiegel I do not believe that there is any U.S. state in which the parents can't agree to this by some means. I wouldn't be confident that this is true in Puerto Rico, however.
    – ohwilleke
    Mar 6, 2019 at 6:13

Your legal name is your legal name and your child’s legal name is their legal name. For legal purposes you have to use your legal name.

When you name your child there is a convention that they take the father’s or mother’s (or both) last name but you can give them any name you like (subject to names the state restricts).

In general usage, you can call yourself and your child can call themselves anything they like - most people have different ‘handles’ in different circumstances.

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    "For legal purposes you have to use your legal name." The common law rule (still the law in Colorado) is that your legal name is what people call you and you answer to, even if it was not your name at birth and you never employed any legal process to change it. See In re Nguyen, 684 P.2d 258 (Colo. App. 1983) and In re Knight, 36 Colo. App. 187, 537 P.2d 1085 (1975). This is one of my favorite laws.
    – ohwilleke
    Mar 6, 2019 at 6:19
  • @ohwilleke New York law on names is also still common law (last I looked into it a couple of years ago). But it seems that nobody has informed the clerks at the DMV about this (nor the US congress, which is responsible for most of the rules they are dealing with).
    – phoog
    Mar 26, 2023 at 20:39

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