Originally Posted by SPEEDBIRD008

With the introduction of the A320 neo, British Airways has opted for large over head lockers (XL). These large overhead lockers are not present on all the British Airways' A320/A321 aircrafts.
The A320-ceo have the original/smaller lockers. Eventhough British Airways have NEO aircrafts, they are all not the same in terms of overhead lockers. These new overhead lockers were introducted in late 2024 and deliveries began Q1 2025.
The registrations of the XL lockers are.
A320NEO:G-TNN(M/N/O/P/R/S/T/U/X/Y/Z) and GTTS(A/B/C/D/E/F/G/H/*)
A321NEO: G-TNE(A/B/C/D/E/F/G/H/I/*)
*upcoming deliveries beyond 2026
So if you fly on a British Airways short haul service, look out for these registrations. These lockers are designed to migitate checking in cabin baggage at the gate. These lockers allow passengers to stack their cabin bags sideways to allow for more to be taken on board as per operational limits.