My DS has had the annual pass with the wheelchair symbol for some years. His green pass has always been for the lifespan of the annual pass, renewed at the same time which we always do at the park. A couple of weeks ago when I renewed his AP and green pass I did have to show DS's blue badge and in fact because the expiry date of the badge happens to be a couple of months earlier than the expiry date of the new annual pass this time, the green pass could only be issued up to that date. I will need to renew the green pass again for the last couple of months of the annual pass's lifespan when the blue badge is replaced. I would have thought that you will certainly need a doctor's letter to get the green pass again despite having the wheelchair symbol.