Not sure if this is the correct forum, but here goes 

My mate has arrived, on 60 visa free, extending it to 90 days  might convert to non O Retirement... He wants to know if he can open a bank accountwhile on visa free, and what bank/banks, he tried Kasikorn but was told he first needs a visa.

This can still be done via-agent.  Usually, this requires one use the agent's services for the retirement extension.  The "money fix" agents will offer some discount on their service, if you use your own 800K. 

 

In what area is your friend living?  Availability of this varies by area.  Hopefully, someone with recent (last few months) experience can recommend an agent who can do it.  There was a recent / further "tightening" of obtaining bank-accounts, so older reports are useless.

2 hours ago, Aussie999 said:

My mate has arrived, on 60 visa free, extending it to 90 days  might convert to non O Retirement... He wants to know if he can open a bank accountwhile on visa free, and what bank/banks, he tried Kasikorn but was told he first needs a visa.

Generally requires a Non imm visa. 

You state "might convert to Non O" 

If that's a yes and he does not have a Thai bank account then he should have obtained the Non O prior to entering Thailand. 

If he does not intend to obtain a Non O then why would he need a bank account. 

Where is he located. 

An agent can assist with bank account however most will require that you use the agent for Non O + 12 month extension. 

Needs to decide what he actually wants