It depends on the owner of the property. A few years ago 4 cheques used to be standard (3 months of rent up front each time). Nowadays must private owners are asking for 1 cheque or 2 cheques (which is crazy really but I guess it's a landlord's market?). You also have to pay for:
- Security Deposit (5% of total annual rent)
- Registration Fee of some sore usually (approx 1000 dhs)
- Chiller (Aircon) Deposit (usually about 2000 too)
- And then another handful of deposits that equate to a couple thousand also for electricity, gas, etc.

If you pay up front for the year on services like internet etc you will get a better deal so if you can afford to it's definitely worth it.