https://awardwallet.com/blog/british-airways-aarp-discount-chase-cardholders/
We just booked Business Class for next May, (LAX to Milan) and saved about $500 a ticket with the "stacked" discounts. Note, one cannot use Avios to discount a price if the Visa discount is used. AARP has extended this offer thru August, 2024, but it's been in place since pre-COVID days.
One starts with the AARP site, which takes a customer directly into British Airways, so the tickets are purchased directly from British Airways. We then pay with the British Airways Visa for an additional 10% discount. (the promotional code is referenced in this article . It seems to change every year.)
These business class tickets are changeable.
AARP is open to any age, and costs about $20 for a couple. The chart indicates discounts per fare class.
I realize there are pros and cons for traveling with only one airline internationally. This choice works for us. Hopefully this will help others.
Good luck and safe travels for all!