English Language Requirement Query - Switch from Tier-2 ICT to Tier-2 General within UK

[MrClientServer]

Dear Experts,
Looking for small clarification with regards to English test
A friend of mine recently got offer in London and the Client has agreed/approved to sponsor TIER2 GENERAL.
So ideally he will be looking to change from Tier-2 ICT to Tier-2 General.

Since he is already in UK for last 8 Years and switching from Tier-2 ICT to Tier-2 General question is Does he need to prove ENGLISH LANGUAGE REQUIREMENT again(either by NARIC or English Test B1)???


Additional Details of his visa :-
COS(Certificate of Sponsorship) approved Date : 30-Mar-2010.
Visa Granted on : 10-May-2010.( Visa Category: Established Staff )
Date Entered in UK : 11-May-2010
Visa Renewed on : 01-May-2011 ( Visa Category: Long term Staff)
The above visa has been renewing every 2 years. The current visa is valid till July 2019.
Overall now he stayed 8 years on TIER-2-ICT.