Even if it's in your contract, you may not get your severance pay if the company is going out of business.
In October 2003, the CBI produced its own guidance for directors on severance pay.
Unless it's in your contract that you will get severance pay if a layoff happens, don't count on it.
Employers are not bound by any laws to give employees severance pay when they tell them they need to pack their things.
