IHG Rewards Club has a “New Stay Bonus” offer for 1,500 bonus points for one stay within 90 days of registration.
You can earn 1,500 bonus points once and need to do it within 90 days after registering for this promotion.
Note that this offer is combinable with all the other IHG Rewards Club promotions that you can find here.
You should sign up for this promotion when you know for sure that you have a paid stay coming up within 90 days. The expiry date of this offer is unclear.
There is another “New Stay Bonus – Test Market Offer” (access here) that is for 3,000 (posted in January) that doesn’t seem to work anymore. This 1,500 points offer did post to a stay done last week.