 In 2006 Allenby was a regular in the Leicestershire side which won the Twenty20 Cup, scoring 64 and taking two wickets in the final against Nottinghamshire.In the same season he made his first-class debut against the touring West Indies A and made his County Championship debut in the final game of the season against Essex.In the latter he scored a maiden first-class century and followed that with 68 not out in the second innings as Leicestershire successfully chased 301.