I have one cell that contains up to 26 different 3 letter facility prefixes, and they are part of 4 different locations with a number code. Example, ASK is part of Facility code 20. I want a formula that will look at cell M and if it the facility belongs to code 18, 20, 21, or 22, it will put that number in Cell N.

I tried to just repeat this formula 26 times in Column N, but Excel says I have too many arguments.

=IF(M2="ASK","20")

here's my first attempt with the 8 codes that belong to #20:

=IF(M2="ASK","20",IF(M2="BOI","20"),IF(M2="SPO","20"),IF(M2="WHC","20"),IF(M2="WAL","20"),IF(M2="ROS","20"))