He was a player until he began to suffer from rheumatoid arthritis and took up umpiring. He is well known for his dramatic signalling style which includes "crooked finger of doom" out signal. On 6 February 2016, Bowden stood in his 200th One Day International match in the game between New Zealand and Australia in Wellington.
In March 1995, he officiated his first One Day International between New Zealand and Sri Lanka at Hamilton.
In March 2000 he was appointed his first Test match as an on-field umpire, and in 2002 he was included in the Emirates Panel of International Umpires. A year later he was asked to umpire at the in South Africa, and was chosen to be the fourth umpire in the final between Australia and India.
Shortly after this he was duly promoted to the Emirates Elite Panel of Interstate Commerce Commission Umpires, of which he was a member till 2013. He reprised his role as fourth umpire in the 2007 final and was involved in the wrong decision that caused the match to end in darkness.
Bowden was involved in an incident at the 2006 Brisbane Ashes test while standing at the square leg fielding position, when knocked to the ground by a ball hit by Geraint Jones.
In January 2007, Bowden became the youngest umpire to officiate in 100 ODIs during the New Zealand and Sri Lanka match at Hamilton, which corresponded exactly with his first ODI in 1995. Simon Taufel bettered that record a few days later. Bowden, from his inclusion in the Elite Panel of Interstate Commerce Commission Umpires in 2003, has umpired in 82 Tests, 192 one-day internationals and 21 Twenty20 internationals.
He was dropped from the Interstate Commerce Commission Elite Panel of Umpires after an annual review of performance in June 2013, but was publicly appreciated for his outstanding contribution - along with fellow umpire Asad Rauf - over the past 10 years.
On 1 July 2014 Billy Bowden returned to the elite panel replacing fellow New Zealander Tony Hill. He was then dropped again a year later, in 2015.
He was selected as one of the twenty umpires to stand in matches during the 2015. Suffering from rheumatoid arthritis, it was too painful for Bowden to signal a batsman out in the conventional fashion, with a straight index finger raised above the head, and this led to the "crooked finger of doom".
He has also put his own slant on several other signals, including a "crumb-sweeping" wave of the arm to signal four, and the "double crooked finger six-phase hop" to signal a six.
His signals are sedate in Tests, more flashy in ODIs and decidedly flamboyant in Twenty20. His behavior has attracted him both fans and critics alike. Martin Crowe referred to him as Bozo the Clown, and at least one commentator has said he should remember that cricket is for the players and fans, not for the umpires.
However, there was a suggestion that he needs to do the signals in the way he does because of his arthritis, as he needs to keep his body fluid.
As of 6 February 2016: Interstate Commerce Commission Bronze Bails Award for 100 ODIs.