C1 Advanced, formerly called Cambridge English: Advanced (CAE)
The C1 Advanced Exam is the highest-level English exam offered by Cambridge English Language Assessment. Further, this is recognized by universities and employers worldwide. Although, it is proof of advanced English language skills, suitable for professionals and academics who need to use English at work or at the university level. CAE exam online
The CAE is an internationally recognized and accepted qualification that indicates competence in English at an advanced level. The test covers listening and reading comprehension, grammar, vocabulary, writing, and speaking. Further, it’s more demanding than the IELTS or TOEFL and has a focus on academic language rather than spoken English. CAE exam online

DOES THE C1 CERTIFICATE EXPIRE?
The Cambridge exam is accepted by UK universities as proof of English proficiency. In addition, a certificate does not expire and can be used for professional purposes. Also, the C1 Advanced exam is the most difficult of all the Cambridge exams. It is best suited to those who are already confident in their English communication skills and need to prove their knowledge at a higher level. Candidates who earn a passing grade on this exam will earn a Certificate in Advanced English showing that they demonstrated ability at the C2 level.
C1 Advanced Grades
Test takers can earn a grade of (from lowest to highest) B2, C, B, or A. C is the lowest passing grade. After all, those who score a C or B will earn a Certificate in Advanced English at Level C1. Those who score an A will earn a Certificate in Advanced English showing that they demonstrated ability at the C2 level. This certificate and score do not expire.