Why can AS level marks only be carried forward within a 13 month period?

Cambridge does not offer a modular approach to assessment. The expectation is that candidates taking an A Level will complete their course within a two-year period. However, we do allow a ‘staged assessment’ approach to the two year course of study, which means that a candidate can complete an AS Level in one series/year and carry forward that whole result to be added to the result for the rest of the A Level within 13 months. 

We have the 13-month rule because a candidate’s achievement in a syllabus should reflect their current level of knowledge and skills. Longer than 13 months means that we are less confident that we are awarding the final qualification grade based on a candidate’s current performance level.

After 13 months there may also be changes to the syllabus or assessment requirements. A candidate with
older marks to carry forward would not necessarily be meeting the content and skills requirements for the current version of the syllabus.