Canceling a nonrefundable ticket
 

Hello, I bought a nonrefundable ticket on US operated by US metal, but had to cancel due to schedule changes. I understand that what I paid for the ticket should be credited back to my account and that I should be able to use the credit for future flights that take place within one year of original travel date? If so, when I try to book a new flight that is cheaper than the original, I am still asked for payment in full... Is there something I am missing here? Do I get the credit back if I cancel a nonrefundable ticket?

It is likely that there is a penalty associated with the ticket. Typically it would be $200 for a domestic ticket and $300 for an international ticket.

Many US tickets also require that the ticket be cancelled prior to the scheduled flight. If you don't, there may be no value.

Rather than torturing yourself, call US directly. If this can wait until the blizzard in the midwest/northeast is resolved, you will find it much easier to get through to US.

How much is your old ticket before penalty and how much is the new one?

I was not aware of a penalty, the terms just said I have to spend original ticket amount of $151 within a year. The new ticket is $141.

If you booked your ticket on usairways.com then on the payment page it would have had the rules for the ticket. If yours is a domestic ticket then it most likely would cost you $200 to change the ticket. As your original ticket was less than $200 it isn't worth changing/canceling the ticket.

Nope, you're thinking of Southwest. Every other airline charges a change fee. In this case, forget about your $151 as it's almost certainly less than the change fee.

It would be one year from date of original ticket issue, not one year from travel date.

By "schedule changes" do you mean changes in your personal plans or changes to the airline's flight schedule? It makes a big difference as far as a nonrefundable ticket is concerned.

My personal plans

You're likely out of luck then. if the carrier had changed schedule then you might be able to get a fee-free change. But if it was just you wanting to change then you're subject to the change fee and, as others have said, thats probably higher than your fare so you effectively have $0 value.

Cancelled Ticket
 

I had a trip planned for the end of Jan which due to personal reason could not take. I cancelled the flight and was told by the agent that I can use the ticket towards travel by the beginning of October.

The ticket cost 550GBP which I assume if the change fee is 300USD/200GBP then the rest will be put towards a new ticket? So about 350GBP off the price of a new ticket/trip?

Do I need to go from the same location, original trip started from MAN but it may be easier for me to get to LHR?

Could I use this towards a ticket on AA plane?

TIA
SM

Unless things have changed recently, you pay the change fee (with a new charge), then can use the value of your unused ticket.