Partial dates of birth leaked: what it means and what to do

What this data is

Part of your date of birth, such as the day and month without a year, or a birth year on its own. Social apps often store it for birthday reminders or age checks.

The risk on its own

A partial date cannot pass an identity check by itself, because banks and government services ask for the full date. The weakness is that the missing piece is easy to find. An age on a profile, a graduation year or a birthday post fills the gap in minutes.

The risk combined with other data

Once completed and joined to your name and address, it becomes a full date of birth, one of the most widely used identity checks there is. That supports telephone impersonation, credit applications and account recovery fraud. Birthdays are also a common password ingredient, so they feed password guessing too.

How criminals use it

• A day and month from this leak is paired with a birth year from another, producing a full date of birth for fraud.
• An attacker tries passwords built from your name and birthday, such as a name followed by the day and month.
• A caller recites your birthday to a phone carrier or utility as part of an identity check.
• A birthday themed phishing message offers a free gift from a brand you use in the week of your birthday.

What to do now

1. Hide the birth year and birthday on Facebook, Instagram and LinkedIn, or limit them to only you.
2. Stop using any password or PIN that contains your birthday, and replace it with one from a password generator.
3. Check whether your full date of birth or age leaked elsewhere with an email breach check.
4. Consider a credit freeze if your address and full name are also exposed.
5. Be sceptical of birthday rewards that ask you to log in through a link.

Frequently asked questions

Is a birthday without the year dangerous?

Only slightly on its own, but the year is often easy to find from an age or graduation date elsewhere. Treat it as one step towards a full date of birth.

Should I remove my birthday from social media?

Yes, or at least hide the year. Friends can still see reminders if you set the audience carefully.

Can a partial date of birth open a bank account?

No. Identity checks need the full date and usually a document too. The danger is when the rest is found elsewhere.

Breaches that exposed this data

• Mashable: 2020-06-01, 1.4M accounts, Auth tokens, Email addresses, Genders, Geographic locations, IP addresses, Names
• GunAuction.com: 2022-12-03, 565K accounts, Browser user agent details, Email addresses, Genders, IP addresses, Partial credit card data, Partial dates of birth
• AhaShare.com: 2013-05-30, 180K accounts, Email addresses, Genders, Geographic locations, IP addresses, Partial dates of birth, Passwords
• Fanpass: 2022-04-30, 112K accounts, Email addresses, Genders, Names, Partial dates of birth, Passwords, Phone numbers
• hemmelig.com: 2011-12-21, 29K accounts, Email addresses, Genders, Nicknames, Partial dates of birth, Passwords, Usernames
• Quitbro: 2026-02-17, 23K accounts, Email addresses, Partial dates of birth, Usernames

Tools that help

• Email Breach Check
• Password Generator
• Privacy Score

Related guides

• Facebook Privacy Settings: The 2026 Lockdown Checklist
• Credit Freeze Guide: US, Australia, UK and Canada Steps
• Identity Theft Checklist: What to Do in the First 48 Hours
• Password Reuse Risk: How Credential Stuffing Really Works