What does attrition mean in a hotel contract?
 It means, “what if”.

What if you guaranteed 100 rooms per night and you only end up needing 80?

What is you guaranteed 100 guests for lunch and only 90 show up to eat?

Attrition is presented in a hotel contract based on a percentage amount that your company will owe the hotel IF you do not meet your guaranteed numbers.

The average % of allowable attrition is usually 15%.  Sometimes a hotel will offer you 20% attrition – always ask!  on the flip side, if a hotel only is offering 10% attrition, ask for no less that 15%.
This means that if you guarantee 100 rooms and the hotel will allow you to reduce that number up to 15% (for example) or only pay for 85 rooms.

Hotels usually ask you to reduce (if you don’t need all the rooms you intended on utilizing) within 30 days of the arrival date.

If you find that you have to pay for 100 guests yet only 85 will be dining, upgrade the menus as you are paying for the difference anyway.