At the moment, OnePlus 2 invites are only good for 24 hours. We can only assume that this was done so that those who decide not to buy the phone will be passed over and given to others who are still waiting for their invites. However we can only imagine how frustrating it can be especially if you’re too busy.
Now the good news is that according to OnePlus, they have decided to extend the validity of an invite to 3 days. This means you basically 72 hours from the time you receive your invite to claim it, after which it will no longer be valid and you will have to find another way to get your hands on the device.
If you think that you can just line up again for another invite, think again. As you might have heard, OnePlus has closed the invite system for the OnePlus 2. The system was closed on the 22nd of October meaning that they will no longer be accepting anymore reservations. However those who are still in the queue will be eligible for the invites, but not new ones.
It is unclear if this closure is permanent, but either way for the foreseeable future if you want the OnePlus 2, you will have to look elsewhere for it especially if you have missed your chance to claim your invite.