Offering instruction that is about banking old money and high loan (11)
I believe the answer is:
educational
'offering instruction that is about banking old money and high loan' is the definition.
'educational' can be an answer for 'offering instruction' (providing education or instruction). I am unsure of the remainder of the definition.
'offering instruction that is about banking old money' is the wordplay.
I cannot really understand how this works, but
'instruction' could be 'education' (synonyms) and 'education' is located in the answer.
'about' could be 'a' (abbreviation in Chambers) and 'a' is located in the answer.
'money' could be 'l' (L can mean 'pounds') and 'l' is located in the answer.
No letters remain.
This explanation may well be incorrect...
(Other definitions for educational that I've seen before include "Providing knowledge" , "Relating to teaching" , "Academic" , "as an aid to learning" , "Didactic" .)