Check Aircraft MSN
Maximum certified landing altitude for the A320 is 14100ft, that's why...
We have a very mixed fleet, so this value ranges from 8000ft up to 14100ft.
The aircraft certified to land above 9200ft have the HIGH ALT p/b on the overhead panel.
Check FCOM 3.01.20 p3 and FCOM 2.04.30 for further details
Have a nice day