A guarantor is legally responsible towards the landlord in the event of a default from the tenant
In most cases, landlords or lessors will ask you to provide a guarantor for your rent in France.
A guarantor is legally responsible in the event of a default from you. He or she brings financial security to reassure your landlord: with a guarantor at your side, the landlord trusts your ability to fully pay your rent in due time.
It is a huge commitment, that's why the guarantor must respect some criteria.