Many Castle super-fans already know the answer to this question, but don't feel bad if you're still in the dark. There was a time when even Castle writer Terri Miller was confused about Kate Beckett's badge number.
Here's the deal:
In Season 2, Episode 14: "Suicide Squeeze," Kate clearly states over the phone, "Beckett. B-E-C-K-E-double T. Badge 41319," However, in Season 3, Episode 16: "Setup," the detective yells, "Badge number 0334!" after she and Castle realize they've been exposed to high levels of radiation.
So, which is it? 41319 or 0334?
Back in May 2011, Terri Miller asked fans to help her identify when the badge number changed so she could address the continuity issue with producers.
"Who knows when Beckett's badge number changed this season and what it should be? A little help please," she wrote. "The badge question: we're trying to get it right, be consistent. I remember someone questioned it, so I wanted to check w/ the experts :)"
Then, a few days later, Terri served up some good news: "@mbthecool19 #TEM We sorted out the badge. Thank you," she confirmed.
In Season 4, Episode 9: "Kill Shot," we can clearly see that Beckett's badge reads 41319. So it's settled Castle fans; you can officially update your lucky number.