Some changes to employment contracts can be deemed to have been accepted by your continuing to work there, some legally require you to formally agree to the rev

Some changes to employment contracts can be deemed to have been accepted by your continuing to work there, some legally require you to formally agree to the revised contract, if you don't you aren't bound by it. This is to prevent employers making detrimental changes to contracts after hiring people. All the above applies to the uk, not sure about other countries.