Can names have numbers? In the United States, the answer splits sharply by context: your legal personal name almost certainly cannot contain the digits 0 through 9, but business names, trademarks, and online identifiers can. Vital records offices restrict birth certificates to alphabetic characters, and courts have refused to let people change their legal name to a numeral. Once you leave personal identity behind, the rules loosen considerably.
Personal Names on Birth Certificates
Most state vital records offices allow only the 26 letters of the English alphabet in a child’s name, along with a small set of punctuation marks. Michigan’s rule is representative: the full name of each person recorded must use English alphabetic characters, upper and lower-case A through Z, plus commas, periods, apostrophes, hyphens, and spaces.
California takes the same approach. Its Office of Vital Records requires birth certificates to be “completed with the 26 alphabetical characters of the English language,” and specifically excludes numerals along with pictographs and ideograms. When Elon Musk and Grimes tried to register their child as “X Æ A-12” in California, the state health department confirmed the name would not be accepted because it contained characters outside the permitted set. The couple reportedly changed the “12” to the Roman numeral “Xii.”
There is one narrow exception. Surname suffixes like “Jr.,” “III,” or “2nd” may be recorded in either Roman or Arabic numerals on vital records. That’s the only slot in a personal name where a digit routinely appears.
A few states are more permissive. Illinois updated its vital records systems to accept names with digits, and South Carolina reportedly allows both numbers and symbols. These states are outliers. The nationwide norm is letters only.
Numbers Spelled as Words
The restriction targets the digit characters themselves, not the concept of a number. Names like “Seven,” “Eight,” or “Trinity” move through vital records systems without issue because they consist entirely of letters. Wisconsin made this logic explicit: when a parent wanted a numeral in a child’s name, the state required the number to be spelled out. So “7” is rejected, but “Seven” is fine.
Changing Your Legal Name to a Number
Adults who try to adopt a numeric name through a court petition have consistently lost. The leading case is Application of Dengler, decided by the Minnesota Supreme Court in 1979. Michael Herbert Dengler wanted to change his name to “1069,” a numeral with personal and philosophical significance to him. A North Dakota court rejected the request first. When Dengler moved to Minnesota and tried again, the state supreme court affirmed the denial.
The court’s reasoning was practical. State name-change statutes were never intended to let a person replace an alphabetic name with digits, and the country’s social and economic systems are built to identify people by letters. The court noted that Dengler was free to petition for a spelled-out version like “One Zero Six Nine.”
A California court reached a similar result with Thomas Boyd Ritchie III, who tried to change his name to just “III.” The court ruled the Roman numeral standing alone would cause confusion because it functioned as a symbol rather than a recognizable name. Even where a name-change statute doesn’t directly ban numbers, courts have treated numeric names as outside what the legislature meant to allow.
Federal ID Systems Reinforce the Same Answer
Federal identification documents will not carry a numeric name through even if a state somehow issued one. The State Department follows International Civil Aviation Organization standards, which do not permit special characters, symbols, or numerals on passports. If an applicant’s legal name contains a numeral, the digit must be crossed out and spelled out as text.
Under federal REAL ID rules, the name and other information printed on the face of a compliant driver’s license must appear in “Latin alpha-numeric characters,” and the regulation defines “full legal name” as an individual’s first, middle, and last name “without use of initials or nicknames.”1eCFR. Part 37 – Real ID Driver’s Licenses and Identification Cards The regulation itself allows digits, but the underlying birth certificate or source document almost certainly did not.
Social Security cards work the same way. The name on your card must match the identity document you submit, and the card provides two lines of 26 character spaces each.2SSA – POMS. How the Number Holder’s Name is Shown on SSN Card A suffix like “III” appears as the source document recorded it.
Business and Entity Names
Business names are the opposite story. Numbers are not just tolerated; they are expressly permitted. The Model Business Corporation Act, which underlies corporate law in most states, provides that a corporate name “need not be in English if written in English letters or Arabic or Roman numerals.”3Legal Information Institute (LII) / Cornell Law School. Model Business Corporation Act 3rd Edition That is why “3M,” “7-Eleven,” and “24 Hour Fitness” exist without legal trouble.
States follow through at the registration level. New York’s rules for entity names say a name may consist of letters of the English alphabet, Arabic and Roman numerals, and symbols capable of being reproduced on a standard English-language keyboard. The name still has to be distinguishable from any existing entity or reserved name on file with the Secretary of State.4New York Codes, Rules and Regulations. 19 CRR-NY 156.2 – Standards
Trademarking a Number
You can register a number as a trademark with the U.S. Patent and Trademark Office, but only if it functions as a distinctive identifier for your goods or services rather than describing them. The USPTO evaluates numbers the same way it evaluates words: the more arbitrary or creative the use, the stronger the mark.5United States Patent and Trademark Office. Strong Trademarks
A number used in an arbitrary or unexpected way registers easily. “WD-40” for a lubricant and “Chanel No. 5” for perfume have no inherent connection to the product, which is what makes them strong. A number that describes the product has a much harder time. An alcohol percentage used as a beer brand, or a number indicating quantity in a package, would likely be refused as merely descriptive because it tells consumers about the product rather than identifying its source.6United States Patent and Trademark Office. Definitions for Responding to a USPTO Office Action
A descriptive numeric mark can still become registrable if the business can show that consumers have come to associate the number with its brand through extensive use and advertising. Evidence typically includes sales volume, advertising expenditures, length of use in commerce, and consumer declarations.6United States Patent and Trademark Office. Definitions for Responding to a USPTO Office Action
Usernames, Emails, and Domain Names
Digits face no meaningful restrictions online. Domain names in the Domain Name System use ASCII characters, which include the basic Latin alphabet, numbers 0 through 9, and hyphens.7ICANN. Frequently Asked Questions Purely numeric domains like “123.com” or “888.com” are perfectly valid and, in some markets, valuable.
Email addresses follow the same permissive standard. Numbers can appear in the local part before the @ symbol, in the domain, or in both. Individual platforms set their own rules for usernames and display names, and nearly all allow digits. Numbers are the most common fallback when the alphabetic handle you wanted is already taken, which is how “JohnSmith” becomes “JohnSmith42.”
The short version: use digits freely for a company, a brand, or a login. For the name that goes on your birth certificate, passport, or Social Security card, plan to spell them out.