Thank you for the replies and I had seen the compensation post containing the Mennens formula and example posted by CWS. I received notice of the downgrade via text and email. It was a discounted A fare when BA was running a sale, not a paid upgrade. This is my first experience with EC261 and I will wait until after the flight to make a claim. The only re-booking that would interest me is changing the departure city to DFW and flying F on the new B78X. I'm not sure BA would do this but I'm also fine flying out of ORD in the A351 club suite. I am unclear how to follow the Mennens example in the compensation thread because my ticket receipt shows a fare of 1299 plus 176 APD, misc taxes and fees of ~105, and a 400 pound 'carrier imposed charge'. The example takes half the fare and subtracts APD plus 2 airport specific fees then multiplies by .75. I guess I would start with half the total which would be 990, subtract 176 APD and 105 in fees/taxes then multiply by .75. This would be 990 - (176+105) x .75 = 532 GBP. I'm not sure what happens with the 400 pound carrier imposed charge.