What's the difference between sublet, subleasing and subletting? Are they all words for the same thing? If sublet is the name of the person who takes over, is that the same as subletor?
Let and lease are variations of the same word; the former is more common in British English and the latter more common in American English.
Leasing is the verb form of lease.
Adding sub to any of them just moves the arrangement down from being between the owner and the tenant to being between a tenant and a (sub)tenant.
This answer relates to U.S. law only.
What's the difference between sublet, subleasing and subletting? Are they all words for the same thing?
Yes, they are different words for the same concept and have identical meanings.
Looking at the root words, let and lease may help to dispell some confusion. An authoritative legal dictionary, Black's Law Dictionary (10th edition 2014), defines them as follows:
let vb. - To offer (property) for lease; to rent out. The hospital let office space to several doctors.
lease vb. 1. To grant the possession and use of (land, buildings, rooms, movable property, etc.) to another in return for rent or other consideration. The city leased the stadium to the football team. 2. To take a lease of; to hold by a lease. Carol leased the townhouse from her uncle.
So, in the legal context, subletting and subleasing are both used to talk about the same same concept leasing property to a third party.
If sublet is the name of the person who takes over, is that the same as subletor?
Subletor is not commonly used in the practice of law–sublessor is favored. However, they have the same meaning. A subletor / sublessor is the person who is making the sublease.
When it comes to legal jargon, an old professor gave me a tip to help decipher some of the terms used in contract/property law. The person ending in -or is the one doing the action of the root work. The word ending in -ee is the person receiving it.
In the UK as an example of jurisdiction . . .
Sublet is a renting agreement.
Sublease is a leasing agreement.
The difference is in the contractual commitments -- see this for a side-by-side comparison.
A Leasehold created through a leasing agreement can be a derivative asset, which can be bought and sold in the same ways stock market derivatives can be bought and sold on the stock market.
A renting agreement on the other hand, does not create a derivative asset or property rights.
A lease is typically for a fixed period of time -- for example 12 months for office space, or 99 years for land use. Where renting is typically from month to month.