Codename Puzzle

Children from the Regency Park neighbourhood are planning a secret party for their parents. They decide to use a simple code to ensure that the parents don’t catch on. The code is that A becomes B, B becomes C and so on. Z becomes A.


You are a part of the party planning group and have just realised that the party decorator is asking for 20% more out of the blue. You want to send the message to your friends.
How do you write “Party planner asking for 20 percent more. What do we do?” in this code? Can you do this in under 1 minute?