I can only presume that somebody had, in the past, obtained a taxi badge,
but was found at a later date, to not have a valid driving licence

So now we've all got to pay £5 for a driving licence check.
I
presume the council can use their 'Goverment Gateway ID' to check licences online for free.
http://www.gateway.gov.uk/Can't remember CBC telling me about this, apparently came into force last April.