Hi , i would like to share the following thought with you and any information is welcoming (and very useful). In December i am thinking of applying for a master degree in universities primarily located in England and Switzerland, and my master will be in maths. I have been trying to find a way to strengthen my application, as my overall degree score is not as good as i think it should be for applying in the top universities of these countries ( such as ETH, UCL or Imperial )
(Although my grades on the courses related to my master are high enough)
So i am thinking of having the GRE test (even if it is not required for any application and it is not mentioned in any math department of any university). Do you know if there are students in the same situation as mine , who had the exam and were benefited because of it? Is a high GRE score considered in the evaluation process?

In the UK we don't use GRE as far as I know. It's really just your undergrad degree that is considered, and possibly A-level equivalents and your interest and enthusiasm for your subject.