Can my job decrease my pay when my assignment in London is over. I'm American working for an American firm.

Question

My pay was increased due to cost of living differences and I will be returning to the US in the next 10 months. I've heard they cannot decrease pay when you return.

Answer 1

You heard wrong.

Answer 2

do you have a contract?

If the cost of living is different and it was allowance for adjustmetn then I would think they COULD rightfully adjust it back to US rates.  

You might have to ask your HR dept so that you know what to expect.