Interval International (II) is an international timeshare
exchange company. You must become a member of Interval International to deposit and exchange timeshare weeks. Interval International has been in existence since 1976. They have hundreds of resorts in more than 80 nations around the globe to choose from. They offer "Getaways" for purchase (instead of trading) and their website is a great research tool (see their "Resort Directory"). Membership fees vary depending on how many years you pay for. If you cancel your membership, you will receive a pro-rated refund. See below for a rate chart.
Tips
Patience is KEY. Understanding that the most desirable resorts and weeks will not be sitting in inventory. It is best to place a REQUEST, and wait for your desired week to be deposited and assigned to you.
If you can't be flexible with your requested dates, try to add as many resorts you can to your request.
See my blogpost for more tips here.
Important Dates
Marriott Owners - Reserve Home Resort: You may reserve a week within the
season you own at your home resort a year in advance if you own one week, or 13
months in advance if you're reserving consecutive or concurrent weeks.
Reservations are available on a first-come/first-served basis and should be
made at least 75 days prior to the start of your season.
Exchange a week with Interval International: You may deposit
a week from your home resort with Interval International (II) and place an
exchange request to travel to another timeshare resort. Plan ahead and deposit
your home resort week at least 60 days prior to the check-in date in order to
avoid late deposit restrictions. Travel must be completed two years after the
check-in date of the week that is deposited. II exchangers may place an
exchange request for the same size villa as what they relinquished (deposited)
from their home resort.
Trade for Marriott Rewards points: You may choose to trade
eligible weeks for Marriott Rewards points by December 31 of the prior year,
and you will receive the Marriott Rewards points by January of the use year
traded for Marriott Rewards points.
Vacation at Your Home Resort: You may reserve a week at your
home resort within the season you own up to a year in advance. Please plan
ahead in order to choose from a greater selection of dates. The latest you
should reserve a week at your home resort is 75 days prior to the start of your
season.