The short answer
Officially the dirham is a closed currency that you should not take out of the country, so spend or change it before you fly. Keep a little back for your last taxi, tip and airport snack, then change the rest at a bureau de change or at the airport before security. Keep an exchange receipt, as you may need to show it.
In more detail
Plan your last day around this. Withdraw less in the final few days so you are not left with a pile of notes. Pay your riad in dirhams if it takes cash, and use the remainder for tips and the airport.
Changing back at Marrakech Menara Airport is convenient, but rates there are weaker than in town. Do it before security. Converting back may require proof that you bought the dirhams in Morocco, which is why holding on to an exchange or ATM receipt helps.
Customs limits can change, so check the current rules before you travel if you are carrying more than a small amount of cash in any currency. If you plan to come back to Morocco soon, some travellers keep a few notes for the next arrival, but the rules are the rules.
Good to know
- Keep a small amount for porters and the airport taxi rank.
- Change leftover cash before security, not after.
- Check current customs limits on carrying cash.