Administration and Liquidation (Don't panic1)

Don't panic we aren't there yet but there's a point I'm not sure about.
I understand the difference between Administration and Liquidation but who initiates the insolvency? Is it the Board or the creditors (which presumably could be Jazza as he could call in the loans)?
I understand the difference between Administration and Liquidation but who initiates the insolvency? Is it the Board or the creditors (which presumably could be Jazza as he could call in the loans)?