If you are not physically on the last leg of a flight, will you be charged a penalty fee by the airlines?

Question

If you are not physically on the last leg of a flight, will you be charged a penalty fee by the airlines?

Answer 1

nope. they will give your seat to stand by.  No penalties. However if you miss a leg of your flight all following legs will automatically be cancelled (Including return flights).  Seeing as this is the last leg of your flight that shouldn't matter.  The airlines really don't care because in their mind, they have your money and now they can sell that seat to someone else.  Double their money.  It's a bonus to them

Answer 2

You're generally fine with not flying the last leg - but if you have any flights left in that itinerary all of your downline flights will be cancelled.  This is not advisable on the outbound flight.

The practice is called hidden city ticketing, and it's technically against most airlines' rules.  While airlines have the right to send a debit memo for the difference in ticket cost to your agent (which they might very well pass along to you), in practice I have not seen this happen in cases where the final leg is dropped.

Good luck and safe travels!