IHG Rewards Club has two “New Member Bonus Promotion” for 3,000 and 1,500 bonus points. These offers do work for Gold & Platinum accounts as well.
You can earn both 3,000 and 1,500 bonus points once. You need to do this within 60 or 90 days after registering for these offers (not sure about the length).
Note that this offer is combinable with all the other IHG Rewards Club promotions that you can find here.
You may get the error message above at the time of trying to sign up for these. It may indicate that you have taken advantage of the same offer previously (could be under different offer code) or the offer is not valid for your account for one reason or another.
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.
If you happen to know, which of the codes is for 1,500 and which one is for 3,000, please leave a message or drop me an email.
There seems to be lot of offers out right now that works for some but not for all.