A plain-English, source-backed explanation of how GCSE and A-level papers are marked, how grade boundaries are set - once marking is complete or nearly complete - and why they change from year to year. England focus.
When your exams finish, there are several careful steps before a grade lands on results day: marking, checks on that marking, and then setting the grade boundaries. Here’s how each part works.
This same marking and standardisation process applies to vocational and technical qualifications - Level 2 Technicals such as BTEC Tech Award, and Level 3 Applied Generals such as BTEC National - just as it does to GCSEs and A levels.
There’s a careful chain between a student sitting an exam and a reliable set of marks:
Source: Ofqual: what happens after your exams · AQA: how exams work.
Because the original marking has already been standardised and monitored, a review of marking looks for a genuine marking error or unreasonable application of the mark scheme - not simply a different opinion.
For some questions there is one clear correct mark. For longer written answers, examiners may need to use professional judgement, so exam boards allow a small permitted range - a tolerance. What matters is that examiners apply the agreed marking standard consistently; their marking is checked throughout, and significant differences are investigated by a senior examiner. Source: AQA ↗
Coursework and other non-exam assessment is usually marked by your teachers using the awarding organisation’s criteria. The awarding organisation then moderates a sample to check marking is consistent between schools and colleges, and can move a centre’s marks up or down so every student is judged to the same standard. Source: Ofqual ↗
A grade boundary is the minimum number of marks needed for a particular grade. Because papers differ in difficulty from year to year, the mark needed for, say, a grade A can change each year. Source: AQA ↗
Boundaries are decided once marking is complete or nearly complete. Exam boards use statistical evidence about the cohort (and previous cohorts) to identify likely boundaries, and senior examiners then review students’ work around those marks, comparing it with work at the same standard from previous years before the final boundaries are set. The data and examiner judgement are used together, so the standard stays comparable year to year. Source: Ofqual ↗ Source: Ofqual ↗ Source: Pearson ↗
They change to reflect how hard the exam was that year. If a paper is tougher than last year’s, the boundaries usually come down; if it’s easier, they may go up. The aim is that the standard needed for each grade stays comparable from year to year. Source: Ofqual ↗ Source: Ofqual ↗
No. A higher or lower grade boundary does not mean one board is easier or harder. Papers differ in difficulty, and boundaries are adjusted so the grade standard stays comparable across boards. Differences in outcomes between boards can also reflect the different groups of students taking each specification. Source: Ofqual ↗
No. In Ofqual’s words: “There are no quotas for the number of students who must pass or fail a subject each year, and no cap on the number of students that can get each grade.” Source: Ofqual ↗
Once boundaries are set, marks are converted into grades and results are issued to schools and colleges, who share them with students. In 2026, A-level (and AS and T Level) results are published on Thursday 13 August and GCSE results on Thursday 20 August. Source: Ofqual ↗
Last checked August 2026. This is a plain-English summary of official guidance; always check the linked Ofqual, JCQ and exam-board pages for the definitive rules, which can change.
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