This variant fist appeared sometime after 1820 in the Burnley area of Lancashire, most likely as a misrepresentation of Wallbank (see here). The "FreeBMD" has records of Woabank birth, burial and marriages upto 1930, the last year for which records are presently transcribed.Subsequent entries in the BMD registers are very likely, but no living Woabanks are recorded on the ONS (Office of National Staistics) database at the Taliesin-arlein site. (names shared by fewer than 5 people are not shown). The Woabank line has therefore either died-out or the surname has been changed.
The FreeBMD records 61 births between 1850 and 1931;27 marriages between 1849 and 1930; and 33 deaths between 1858 and 1930. Almost exclusively, the event was registered at the Burnley Register office, with the odd one at London registration districts: Poplar, West Ham, Rochford and Hackney. One marriage was recorded in Dewsbury in 1872. The full list is here (pdf file).
David Baxter believes that John Walbank b.1790, brother of his ancestor, Mary Walbank b.1793, changed his name to Woabank sometime after his marriage in 1817.The 1841 census for Briercliffe records John Woabank. aged 50, his wife Sarah, and five sons (or relatives) aged from 3 to 20. It is quite possible that older sons were living elsewhere. It is, therefore, possible that all the Woabanks recorded in FreeBMD are descendants of the John Wallbank.
For the discussion on the Woabank name at the Briercliffe Society Forum, go here:
A Hannah Woabank is shown in the IGI as baptised at Rawdon in 1763. This is an isolated entry and may well be a result of the vicar's perception of the name as spoken to him.