The leader per www.boxrec.com who went an entire career without winning a fight was Bheki “Beck’s-Tiger” Moyo who was born in South Africa but did all of his fighting in the UK.
Moyo made his debut in July of 2005 ending it in March of 2015. His overall record was 0-73-2 only stopped 6 times. He was only suspended once and that was for 28 days after his third loss. He died at the age of 42.
There have been 12 boxers who have had at least 40 fights without a win of which 4 are currently active. Next on the list is Alexandru Manea of Romania who was 0-54 stopped 14 times. Manea lost to currently active Yakup Saglam, 43-6, when Saglam was 22-0 and Manea was 0-50. Manea has fought in numerous countries from September of 2000 to November of 2013.
Curtis Gargano, 0-51-1 from the UK fought from 2013 to 2018. Only in his debut did he have a draw. He was only suspended 3 times with the last one after his final fight. Carlos Rocha Tomar, 0-48-1, was from Portugal. He fought from February 1993 to November of 2000. He was stopped 18 times and never suspended.
Alec Bazza, 0-47-3 is from Northern Ireland and still active being stopped 8 times and suspended 7 times. Only 2 of his 49 fights were in Ireland with the rest in the UK. He fought from 2013 to 2019. Scott Hillman, 0-47 stopped 8 times and suspended 6 times. He is still active turning pro in 2015 and from the UK. Marius Sorin, 0-47-2, stopped 32 imes and is from Romania and still active turning pro in 1997.
Rafael Piotrowski, 0-46-1 was stopped 7 times. He is from Poland active from 2003 to 2014. Kalman Vagyocki, 0-45 was stopped 34 times and from Hungary. He was suspended 15 times. He fought from 2011 to 2017.
Szabolcs Gergely, 0-43 was stopped 29 times and is from Hungary. He fought from 2001 to 2012. He was suspended 11 times. Dionisio “Diony” Rodrigeuz, 0-42 stopped 29 times is from Dominican Republic and never suspended. He fought from 2000 to 2016. Viktor Galien, 0-40 stopped 31 times is from Slovakia. He was suspended 13 times by the Hunagian and Czech Union and is still active turning pro in 2013.