Someone who has the same birthday as you is most commonly called your birthday twin. You can also use informal expressions such as birthday buddy, birthday match, birthday mate, or simply birthday sharer. “Birthday twin” is the clearest and most widely understood of these options.
Birthday-Twin Terms at a Glance
- Birthday twin
- Birthday buddy
- Birthday match
- Birthday mate
- Birthday sharer
Does “Birthday Twin” Mean the Same Year?
Usually, no. In everyday use, birthday twin generally means that two people share the same day and month of birth. They do not have to be the same age. If the year also matters, it is clearer to say that you were born on the same date or that you share the same full date of birth.
Birthday twin
The most common informal term. It usually means someone who shares the same month and day of birth as you, even if you were born in different years.
Example: “I just found out that Priya is my birthday twin — we were both born on 14 March.”
Birthday buddy
Friendly and casual. It is less established than “birthday twin,” but its meaning is immediately clear.
Example: “Happy birthday to my birthday buddy!”
Birthday match
A simple descriptive phrase for someone whose birthday matches yours.
Example: “We discovered we’re a birthday match when the office calendar went around.”
Birthday mate
Informal and especially natural in British English, though it is not a fixed dictionary term.
Example: “My birthday mate and I always send each other a message on the day.”
Birthday sharer
A literal, neutral description when you do not want the playful feel of “birthday twin.”
Example: “There are three birthday sharers in our class this year.”
Which Term Sounds Most Natural?
Birthday twin is the best choice in most casual situations because people are likely to understand it immediately. Birthday buddy is warmer and more playful, while birthday match works when you are describing the coincidence itself. “Birthday mate” and “birthday sharer” are understandable alternatives, but they are descriptive phrases rather than established terms.
What About “Birthday Soulmate”?
You may occasionally see playful phrases such as birthday soulmate, but they suggest a special emotional or spiritual connection that simply sharing a birthday does not imply. If you only mean that two people were born on the same day of the year, “birthday twin” is much clearer.
The Short Answer
If someone asks, “What do you call someone who has the same birthday as you?”, the simplest answer is: your birthday twin.