The admission process in US universities will close soon, and most future students have occurred on a wait list. In case you are on a wait list, this means your university application has neither been denied nor accepted, as wait listed applicants know the final results of their university application by June and July.
Many UK universities receive much more applicants than it is possible for them to accommodate. Thus, UK universities stick to a rolling admissions policy – they evaluate the applicant pool – the wait listed applicants are accessed along with intrant applicants. When some students on a wait list get admitted in the end, everyone may not be such lucky. Thus, you should be prepared to answer such an ultimately plan with a back up. When you have a settled seat at other colleges, you should consider accepting this offer.
Being on a wait list does not signify your application is imperfect. So, should you send in extra materials? You may when you have optional essays, letters of recommendations, or other info that you have not shared with admissions offices. Some universities recommend such a practice. You need to think about all the activities that you took part in since you final applied to the college. Is there any achievement, which will make the application much stronger? If it is so, you need to consider delivering this info to the UK universities and colleges. But you need to avoid the practice of delivering a recommendation letter or essay just for it.