In 1901 Bacup rejoined the Lancashire League, where they remained for two seasons before becoming founder members of the new Division Two of the Lancashire Combination in 1903. They remained in the division until the end of the 1910–11 season, when despite only finishing sixth, they were promoted to Division One; that season also saw them win the Lancashire Junior Cup. However, they were relegated back to Division Two the following season after finishing bottom. After three more years struggling at the bottom of Division Two they left the league in 1915. Following World War I, the club rejoined the league in 1920, by which time they had been renamed Bacup Borough. They remained members of the now single-division Lancashire Combination until World War II, finishing in the bottom half of the table in most seasons, one of the exceptions being a third-place finish in 1929–30.