My one involved instruction for a bank cheque (5,5)

I believe the answer is:

money order

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'bank cheque' is the definition.
'money order' can be an answer for 'cheque' (thesaurus). I'm not certain of the 'bank' bit.

'my one involved instruction' is the wordplay.
'involved' is an insertion indicator.
'instruction' becomes 'order' (an order to do something).
'my' placed around 'one' is 'money'.
'money'+'order'='MONEY-ORDER'

'for a' is the link.

Can you help me to learn more?

(Other definitions for money order that I've seen before include "Means to pay" , "way to make payment?" .)

I've seen this clue in The Daily Express.

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