Do GCSE's matter?

Choices don’t really matter too much, as long as you’re doing the core higher-level GCSE papers with a good mix of sciences and essay-based subjects. If your school offers it, do GCSE further maths because it will provide a good bridge between GCSE and A-level Maths (and even A-level Further Maths), but it is not necessary. Most students on the economics tripos have achieved a majority of grade 9s (out of 10-12 subjects), some with a few 8s and 7s. GCSEs are not the defining point for an application, but they are a key indication of your academic performance relative to others. It is unlikely that a few non-9 grades will drastically reduce your chances BUT a majority of grades below 8-9 range will render your application uncompetitive (especially for Oxford, where a lower proportion of candidates are interviewed, and the competitive London universities).