Do I need to achieve the required test scores in one sitting?

Ideally, you will be able to demonstrate that you meet the standard in one test sitting. However, National Boards will accept results from a maximum of two test sittings in a six month period so long as certain minimum scores are achieved in each sitting. These vary from test to test and are outlined in the standard. Note that this does not mean that you can only sit the test twice in the six month period; you may sit the test more than twice if you wish (although this is not recommended by the testing authorities). However, only the results from two sittings will be considered by National Boards.