The amount of the deposit can be via a pact with the agreement of all parties. A deposit for properties used for the sole purpose of a dwelling is governed by the law and the amount payable is the equivalent of one months rental. For a commercial rental the landlord can insist in two months deposit and some other type of guarantee such as a bank bond.
The law states:Article 36. Bond.
1. At the conclusion of the contract, the requirement and provision of a cash depost in an amount equal to one monthly rent in the rental of dwellings and two in the lease for use other than that of the dwelling shall be mandatory.
2. During the first five years (or 7 if the landlord is a business) of the contract, the deposit will not be subject to updating. But each time the lease is extended, the lessor may demand that the bond be increased, or the lessee that decreases, until it becomes equal to one or two monthly rent of the current rent, as appropriate, at the time of the extension.
3. The updating of the deposit during the period of time in which the agreed term for the lease exceeds five years (or 7 if the landlord is a business), will be governed by the stipulated for the purpose by the parties. In the absence of a specific agreement, the agreement on updating the rent will be presumed that there will also be an update of the deposit
4. The balance of the cash deposit to be returned to the lessee at the end of the lease shall accrue the legal interest, after one month from the delivery of the keys for the same without the said restitution.
5. The parties may agree on any kind of guarantee of compliance by the tenant with their lease obligations in addition to the cash deposit.