Your Sri Lankan National Identity Card number isn't random. It contains your year of birth, the day you were born and whether you're male or female, and you can read all of it in a few seconds once you know the pattern. This is also why application forms sometimes check that your NIC matches the birthday you typed.
The two formats
| Format | Example | Issued |
|---|---|---|
| Old | 853400937V: 9 digits and a letter | Before 2016 |
| New | 198534000937: 12 digits | From 2016 |
Both formats are still valid. People with an old card get the new format when they renew or replace it.
Reading an old NIC number
Take 853400937V:
- 85: the year of birth, 1985.
- 340: the day of the year you were born. For women, 500 is added, so a woman born on the same day would have 840.
- 0937: a serial number and a check digit.
- V or X: V originally meant the holder was eligible to vote; X meant not eligible. Today it doesn't change anything about the card.
Reading a new NIC number
Take 198534000937:
- 1985: the full year of birth.
- 340: the day of the year, with 500 added for women, exactly as before.
- 00937: the serial number and check digit.
Turning the day number into a date
The day number counts from 1 January, as if every year were a leap year, so February always has 29 days. Day 340 is therefore 5 December: January to November add up to 335 days (with a 29-day February), and five more days takes you to 5 December. Because of this rule, the same day number always means the same date, whatever the year.
Working it out by hand is easy to get wrong by one day, so use the NIC number decoder: type the number and it shows the birthday, age, weekday and gender, and converts between the old and new formats.
Converting an old number to the new format
The new number is built from the old one in three steps:
- Write 19 in front of the first five digits:
85340becomes1985340. - Add a 0.
- Add the last four digits, without the letter:
0937.
So 853400937V becomes 198534000937. This is useful when a form only accepts 12 digits.
Why a NIC might not decode
- A mistyped digit, especially in the day number, can give a day that doesn't exist (such as 370 or 870).
- Some forms require capital V or X; others accept lowercase.
- A number from another country's ID card won't follow this pattern.
Your NIC number is personal information. Only give it to organisations that really need it, and be careful about posting photos of your card online.