There is no federal list of banned baby names in the United States, and the Supreme Court has treated parental decisions about children as a protected liberty. What you can’t name your child in America comes down to a patchwork of state rules and a few hard technical limits: numerals and symbols are almost universally rejected, a handful of states bar obscene names, diacritical marks are accepted in some states and not others, and the Social Security Administration caps what will actually fit on a card. Beyond those boundaries, most names, including ones that sound like titles or ranks, are legal.
Numbers and Symbols Almost Never Work
The most common reason a birth certificate name gets rejected is technical. Most state vital records systems only process the 26 letters of the standard English alphabet plus hyphens and apostrophes. A numeral, an “@” sign, a slash, or any other symbol either can’t be entered or is prohibited by regulation. The database software predates creative naming by decades, and the rules reflect that.
Roman numerals like III or IV generally pass because they’re built from ordinary letters. Arabic numerals do not. In a 1979 Minnesota Supreme Court case, a man’s petition to legally change his name to “1069” was rejected; the court suggested he could spell the number out in words instead. The characters themselves were the problem, not the idea.
Diacritical Marks Depend on the State
Accents, tildes, and umlauts are a split issue. Texas, Illinois, Kansas, Hawaii, Oregon, Alaska, and roughly a dozen other states already accept diacritical marks on vital records. California, which had long required plain English letters, signed the Name Accuracy Act into law in 2025 to allow characters like ñ and é on birth certificates and other vital records.
Plenty of states still lack the systems or statutory authority to record these characters. If the name you want includes a diacritical mark, call your state’s vital records office before the birth. It’s a short call that avoids a long correction process.
Obscene and Offensive Names
A small number of states explicitly ban obscene or vulgar names on birth certificates, giving vital records officials discretion to reject profanity, slurs, or deeply offensive language. The usual legal justification invokes the child’s welfare. Actual rejections are rare because few parents try to register names that cross the line.
Provocative names that aren’t textbook obscenity sit in a harder zone. A New Jersey couple named their son Adolf Hitler Campbell; the state did not reject the name on the birth certificate. Even when a name strikes most people as offensive, the government’s power to block it is limited unless a specific statute or clear constitutional basis applies.
Titles, Ranks, and Religious Names
You’ll hear that states forbid names suggesting a title of nobility or official rank. The reality is much narrower. King, Duke, Major, and Prince are common first names, and no state routinely rejects them. The concern, where it exists, usually involves names that function as professional credentials, like “Dr.” or “Judge,” claimed by someone without the credential. Enforcement is inconsistent even there.
The most-cited “title” case actually shows how strongly courts protect naming freedom. In 2013, a Tennessee magistrate ordered a baby’s first name changed from “Messiah” to “Martin,” writing that the title belonged only to Jesus Christ. The decision was overturned within a month on Establishment Clause grounds, the baby kept the name Messiah, and the magistrate was later removed from the bench, in part because of the ruling. An official’s personal or religious objection is not a legal basis to reject a name.
Surnames Are Largely Open
In most states, a child does not have to carry either parent’s last name. Parents named Jones and Brown can name their child Smith. They can hyphenate, combine the two, or invent a new surname entirely. Before the 1970s, many states gave fathers an automatic right to have children bear their surname; courts struck those laws down on equal protection grounds, and the choice now belongs to the parents.
Unmarried parents face one wrinkle. If the father’s name is to appear on the birth certificate, most states require a signed voluntary acknowledgment of paternity or a court order. That affects whether the father is listed, not what surname the child receives.
The Social Security Card Sets a Practical Ceiling
Even when a state will record an unusual name, the Social Security Administration imposes its own limits, and a mismatch between the birth certificate and the Social Security card creates administrative problems for years. The SSA’s enrollment system accepts only letters, spaces, hyphens, and apostrophes. No numbers, no symbols, no diacritical marks. Its name fields allow 16 characters for a first name, 16 for a middle name, and 21 for a last name.1Social Security Administration. RM 10205.125 Entering NH’s Name in SSNAP
The physical card is tighter. The first line holds 26 spaces for the first and middle names, and the second line holds 26 spaces for the last name and any suffix. If a name exceeds those limits, the SSA abbreviates or drops the middle name to fit as much of the first and last names as possible.2Social Security Administration. RM 10205.120 How the Number Holder’s Name is Shown on SSN Card A name your state will accept but the SSA will truncate becomes a nuisance at school enrollment, on tax returns, and at every identity check for the rest of your child’s life.
If the State Rejects the Name
A refusal from a vital records office is an administrative decision, not a final answer. Start by asking for a written explanation of why the name was denied. Some rejections come from clerical errors or overzealous staff rather than real legal prohibitions, and a written appeal within the agency can resolve the issue.
If the internal appeal fails, the next step is a petition in court. Courts weigh the state’s justification against the parents’ right to name their child, and states face a high bar: the government generally needs to point to a specific statute or a concrete harm, not just an official’s distaste.3Legal Information Institute. Troxel v. Granville Court filings for a name petition typically run between $150 and $500 depending on jurisdiction, and amending the birth certificate afterward carries a separate, usually modest fee from the vital records office. Many parents handle straightforward petitions without an attorney.