The International English Language Testing System (IELTS) measures the language proficiency of people who want to study or work where English is used as a language of communication. It uses a nine-band scale to clearly identify levels of proficiency, from non-user (band score 1) through to expert (band score 9). If you are thinking about matriculating in the UK, the IELTS is required. To register, go here. To practice the IELTS, go here.