Despite close cultural and historical ties, the United States and United Kingdom (U.K.) education and examination systems differ greatly. As a result, running into difficulty can be common when attempting to find equivalencies at all levels of education. The differences in the high school systems, however, make equivalencies markedly more difficult: While a U.S. student receives single high school diploma, the U.K. secondary education system gives a typical student from five to 10 General Certificate of Secondary Education (GCSE) awards, often of varying accomplishment. For U.S. universities and similar institutions, however, this should prove to be a little obstacle.
Check your number of GCSE passes. (For practical purposes, assume a "pass" to be grade C or above). According to the British Council's website, five GCSE passes are the equivalent of one high school diploma.
Find out how many GCSE passes are required by your chosen U.S. institution. This information is usually found within information about international student admissions.
Inform your chosen U.S. institution of your GCSE grades. Do this through the appropriate admissions system or, if necessary, through e-mail.
In the unlikely event that multiple GCSE grades are rejected, it is possible to take a General Education Development (GED) examination, which is a U.S. high school equivalency test, in order to qualify.