Date of Birth definition

A person’s date of birth (DOB) denotes the day, month and year that an individual was born on.

This is an essential piece of personal data, that is often used on official ID documents, such as your passport, driver’s license, and official birth certificate.

Knowing where your date of birth can be found and how it should be correctly written on important applications and documents is critical in many situations.

Find out below how your date of birth works, what format it should appear in, and when you might need it.

When is it Necessary to Prove Your Birthdate

There are many situations when you may be asked to note down your birthdate so you can be easily identified.

Your date of birth is most frequently used to distinguish you from other individuals who have the same name and surname.

It is also sometimes needed to ensure you are over 18 years old and have the legal capacity to enter in to agreements and contracts.

It is usually necessary to provide DOB information on the following:

  • Government documents
  • Tax return forms
  • Official ID
  • Job applications
  • Legal forms
  • Contracts

What is The Correct Format for a Date of Birth?

In the United States, it is common to abbreviate a person's date of birth by displaying the digits of the month, day, and year.

On most documents, you will be required to enter your date of birth abbreviation in the following format:


This differs to the format used in Europe which places the day of the month first. Therefore, it is essential not to confuse these forms of writing your birthdate on official documentation in the US.

Documents That Prove Your Date of Birth

Your date of birth can be found on many vital records and identification documents.

It is possible to use the following to prove your precise birthdate if required:

  • Birth Certificate
  • Passport
  • Driver's license