Here are two numbers from UCAS that explain more about the sixth form than any league table.
Around half of UK 18-year-olds were predicted AAA or above in 2025. Twenty six per cent of accepted applicants actually secured AAA or above.
That gap is not a scandal and it is not a conspiracy. It is the predictable result of a system in which the people who teach a child are also the people who forecast their grades, and in which the forecast is made nine months before the exam. Mocks are the main evidence those forecasts rest on, which is why the mock season running through November and December matters more than its reputation as a practice run suggests.
This is a guide for parents on what a mock grade is actually telling you, how it turns into the number universities see, and what to do when the number is bad.
What a Mock Grade Is, and What It Is Not
There is no national mock. There is no standardisation across schools, no common paper, no agreed grade boundary. One college's mock is a past paper marked to last summer's boundaries; another's is a bespoke paper marked to a boundary somebody set in a meeting.
So a mock grade is a measurement taken with an instrument the school built itself. That makes comparison between schools meaningless and comparison within one school quite informative.
Three consequences follow, and all three are worth knowing before you react to a grade.
A harsh mock is often deliberate. Plenty of departments mark mocks to boundaries deliberately set above the real ones, on the reasoning that a frightened Year 13 in December works harder than a complacent one. If your child's whole class came out a grade below expectation, that is a policy rather than a collapse.
A generous mock is more dangerous than a harsh one. It produces an optimistic prediction, which produces five offers the student cannot meet, which produces Clearing in August. The kind mock is the one to query.
Coverage matters more than the grade. A December mock in most subjects examines perhaps 60 per cent of the specification, because the rest has not been taught. A grade C on two thirds of a course is not the same object as a grade C on all of it, and the honest question to ask the school is not "what did they get" but "what was on it".
How a Mock Becomes a Predicted Grade
This is the part most families never see explained, and UCAS publishes the rules.
A UCAS predicted grade is defined as "the grade of qualification an applicant's school or college believes they're likely to achieve", in positive circumstances. Note who holds the pen: the school, not the exam board, and not the student.
UCAS sets out five principles for arriving at one.
| Principle | What UCAS says |
|---|---|
| Achievable | A prediction "should be based on demonstrable evidence of performance" |
| Objective and data-driven | "you could look at past performance, internal assessments, or current student work to inform your predictions" |
| Comprehensive | "UCAS predicted grades should be made for all pending qualifications", unless the structure of the qualification makes that impossible |
| Determined by professional judgement | "Predicted grades should be set independently of an applicant's university or college choices" |
| Finalised by submission | Universities see only the prediction submitted with the application |
Read the fourth one twice, because it is the one parents most often try to push against. A prediction is not supposed to be adjusted upwards because the student has applied somewhere that asks for A*AA. A college that moves a grade to fit a choice is doing the opposite of what UCAS asks, and is also setting the student up to miss an offer.
UCAS also recommends that a centre has a written, transparent predicted grades policy, shared with staff, students and parents, and ideally agreed before the assessments that inform the predictions take place.
That is the single most useful thing in this article. Ask for it. A good sixth form has one and will hand it over. A college that cannot produce one is predicting grades by instinct, and you have learned something.
The Timing, and Why November Is the Decision Point
For a Year 13 applying this cycle, the order of events is roughly:
- November and December. Mocks sat and marked. For most students this is the last substantial piece of evidence before a prediction is finalised.
- November to January. The reference and predicted grades go onto the application. Students applying to Oxford, Cambridge, medicine, dentistry and veterinary science were already done by the 15 October deadline; everyone else works to the January deadline.
- January onwards. Offers arrive against the prediction. Nothing about the prediction can be changed at this point: it is fixed at submission.
- May and June. The real exams.
- August. The gap between the two numbers becomes everybody's problem.
The practical point is that steps 3 to 5 are all downstream of step 1. By the time an offer looks unrealistic in February, the evidence that produced it was gathered in a hall in November.
Our UCAS 15 October deadline guide covers the earlier route and the Oxbridge interview preparation piece covers what December looks like for that group, who are sitting mocks and interviewing in the same fortnight.
What to Do With a Bad Mock Grade
A short sequence, in order, and the order is the point.
1. Find out what was on it
Before anything else. Which topics, what proportion of the specification, and marked to whose boundaries. A grade is uninterpretable without those three facts and the school has all of them.
2. Read the script, not the grade
Ask for the paper back. Nearly every poor A-level mock is one of four things, and they need completely different responses: content not known, content known but not retrieved under time pressure, question not understood, or time ran out. Revision fixes the first. Nothing but practice under a clock fixes the second and fourth.
Parents usually respond to a bad mock by buying revision guides, which addresses the one cause that was probably not the problem.
3. Ask what the prediction will be, and on what basis
Directly, and in writing if the answer is vague. You are entitled to know what number is going on your child's application and which evidence produced it. If the answer is "we will see how they do in the January assessments", that is a good answer and it gives you a date.
4. Decide whether the problem is academic or not
This is the one that gets missed. A sharp drop in one subject is usually academic. A drop across every subject at once rarely is. Our piece on exam stress, and telling lazy from ill from overwhelmed is the guide to that distinction, and it is worth reading before the conversation rather than after it.
5. Only then consider the structural options
If the mocks confirm that the current setup is not working, the options are real but they are not emergencies: dropping a fourth subject, changing to a different specification at a new college, or in the worst case planning for a retake year. None of those should be decided in the week the results come out.
What a Good Sixth Form Does Differently Here
Mocks are one of the clearest places to see the difference between a school with 200 in a year group and a college with 20.
A large school marks mocks to a departmental standard, issues a grade and moves on. There are too many scripts for anything else, and the feedback a student gets is a number and a page of comments.
A tutorial college can do the thing that actually changes outcomes, which is to sit with a student and go through the script question by question, working out which of the four failure modes produced each lost mark. That takes an hour per subject and it is not available at scale.
The same asymmetry applies to the prediction itself. A tutor teaching six students has seen every piece of work each of them has produced. A teacher with ninety has a spreadsheet. Both can predict honestly; one has far more evidence. We go through that trade in more detail in is one to one education better for sixth form students.
Frequently Asked Questions
Do mock exam results go to universities?
No. Universities see the predicted grade and the reference, not the mock grades themselves. Mocks matter because they are the main evidence the prediction is built on, not because anybody outside the school reads them.
Are mock grades standardised across schools?
No. There is no national mock, no common paper and no agreed boundaries. Each centre sets its own paper and its own marking standard, which is why a mock grade from one school cannot be compared with one from another.
Can a predicted grade be changed after the application is submitted?
No. UCAS states that universities see only the prediction submitted with the application. That is why the conversation about what the prediction will be has to happen before submission, not after an offer arrives.
How accurate are predicted grades?
Less accurate than most families assume, particularly at the top. UCAS reports that around half of UK 18-year-olds were predicted AAA and above in 2025, while 26 per cent of accepted applicants secured AAA and above. UCAS also says the gap has widened over the longer term, especially at the highest grades.
Should I ask the school to raise my child's predicted grade?
Ask how it was arrived at, not for it to be raised. UCAS is explicit that predictions "should be set independently of an applicant's university or college choices", so a request to move a grade to match an offer is asking a college to break the guidance. An inflated prediction also produces offers the student cannot meet.
My child did badly in a December mock. Is the year lost?
Almost certainly not, and the reason is coverage: a December mock usually examines only part of the specification, with months of teaching still to come. The real question is which of four things went wrong, content, recall under pressure, comprehension or timing, because they need different fixes.
Does a harsh mock mean the teaching is bad?
Not on its own. Many departments mark mocks above the real boundaries deliberately, to motivate. If a whole class came out a grade down, that is the likely explanation. If one student dropped and the rest did not, it is worth a conversation.
What should I ask a sixth form about mocks before enrolling?
Three things: when mocks sit in the year, how much of the specification they cover, and whether the college has a written predicted grades policy it will share. UCAS recommends centres have one and share it with parents, so the answer tells you a good deal about how the place is run.
The Short Version
A mock grade is a school's own measurement on a partly taught course, and it is the evidence that becomes the number universities judge your child on. Ask what was on the paper, ask to see the script, and ask for the predicted grades policy.
The guidance centres work to is on the UCAS advisers' predicted grades page, and UCAS's own analysis of the prediction gap is in its news item on predicted grade reports.
If you want to talk through what the mocks are telling you about whether the current setup is right, our university application support page covers what good help looks like at this stage.
