Cognomen Tandaan (Tandaan 
) , in all the world, is a rare family name. The family name Tandaan is habitual in Philippines, where it is a rare surname, Singapore, where it is a very rare surname, and the United Kingdom, where it is an extremely rare surname. Not in comparison with a country's population, the name is most common in Philippines, Singapore, and India. Very seldom, Tandaan is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Tandaan | India, Philippines, Singapore, United Kingdom |
Jay, Randy, Racel, Romeo, Rolly, Roger, David, Lerma, Liezl, Lorry, Janet, Jaime, Jason, Jesus, Jerry, Jeron, Juana, Jinky, Teddy, Naomi, Novie, Elvin, Ramil, Ramir, Ramon, Ariel, Wyn, Mely, Alex, Alan, Aiza, Roma, Rene, Ruel, Ryan, Lani, Eldie, Lily, Jane, Jose, Joel, Noli, Erma, Emma, Mario, Merly, Susan, Angel, Liza, and Ester