For the last few years, there has been a lot of focus on pupil attendance. In our Autumn Term update, we saw that rates of absence remained above pre-pandemic levels, particularly at secondary, where pupils missed around 45% more school than they did in Autumn Term 2019.

A big factor is the increase in the amount of absence which is “unauthorised”.

Absence is recorded as unauthorised in the following situations:

• parents or carers haven’t contacted their child’s school to provide a reason, or
• they have, but the reason falls outside of the limited circumstances in which a school can authorise an absence[1], or
• the reason is one which could, in principle, be authorised, but the school deems the parent or carer to have provided insufficient evidence.

Unauthorised absence accounts for around 30-40% of all missed sessions. At primary, rates are around 50% higher than pre-pandemic. At secondary, they’ve almost doubled.

So today we’re going to take a more detailed look at the patterns behind the headline figures. For example, are a small number of pupils responsible for the bulk of unauthorised absence, or do most pupils contribute a little? Are pupils missing big chunks of school every so often, or regularly missing the odd day?

To answer these questions, we’ll be using data submitted by our 10,000 Attendance Tracker schools over the last academic year, 2024/25.

We’ll look both at the volume of absence recorded, and also the number of “spells”. A spell of absence is made up of a number of consecutive sessions missed. For example, a pupil who was present all week apart from Wednesday records one spell of absence lasting one day. Another pupil who missed four consecutive weeks of school also records one spell, but lasting four weeks[2]. For this post, we’ll just be looking at spells of unauthorised absence.

Spell length

Let’s start by looking at how long spells of unauthorised absence tend to last. We’ll look at this from two angles: firstly, how many spells of each length were there and, secondly, how many days of school were missed due to spells of each length.

The top panel shows a very similar pattern at both primary and secondary: a large majority of unauthorised absence spells lasted a single day (almost 80% of spells at both primary and secondary).  Longer spells were relatively rare, with fewer than 10% lasting longer than three days.

However, despite being most common, single day spells were not responsible for the majority of unauthorised absence. At both primary and secondary, just under 40% of all sessions missed due to unauthorised absence were down to spells lasting a single day, with just over 60% down to spells lasting longer.

Despite making up just over 1% of spells, absences lasting more than two weeks were responsible for 15% of unauthorised absence at primary, and 22% at secondary.

Spell frequency

Let’s turn now to frequency of unauthorised absence. Here, we aggregate spells at the pupil-level, and count the number of spells of unauthorised absence each pupil had across the year. Below, we plot the percentage of pupils by this number.

Surprisingly, perhaps, the proportion of pupils with at least one unauthorised absence (the sum of each set of bars) was similar at primary (54%) and secondary (60%). The distributions, however, are slightly different, most notably at the top end. At primary, 2% of pupils had 15 or more spells of unauthorised absence, whereas at secondary, 7% of pupils did.

At both primary and secondary, the most common number of spells of unauthorised absence was one – 26% of primary pupils had a single spell across the whole academic year, and 20% of secondary pupils.

Let’s look now at the proportion of unauthorised absence accounted for by pupils in each frequency grouping. (So, for example, the bar for one spell tells us the proportion of unauthorised absence sessions which belonged to pupils with a single spell of unauthorised absence.)

Now the distributions are quite different. We see that, at secondary, almost half (48%) of unauthorised absence was down to those with 15 or more spells, whereas at primary, these pupils contributed less than a quarter (22%).

At the opposite end of the distribution, 23% of unauthorised absence at primary came from pupils with a single spell, compared with just 8% at secondary.

We can also look at this same information from a slightly different angle: the proportion of total sessions missed due to unauthorised absence by pupils in each frequency band.

The biggest difference by far between primary and secondary is the contribution from pupils absent very frequently. Pupils with 15 or more spells of unauthorised absence across the year added 1.7 percentage points to the unauthorised absence rate at secondary, compared with 0.4 percentage points at primary.

Finally, we consider how pupils’ characteristics varied by the number of spells of unauthorised absence they recorded. We find that pupils with a large number of spells were much more likely to be disadvantaged (as measured by FSM6) and to have an education, health and care plan (EHCP) than both those with no spells and those with only a small number.

Summing up

Most pupils at both primary and secondary had at least one unauthorised absence in the 2024/25 academic year. The majority of these pupils only had a handful of such absences across the year. And the absences tended to be short, with around 80% lasting a single day or less.

However, small numbers of longer spells, and small numbers of pupils with large numbers of unauthorised absences made outsized contributions to the overall unauthorised absence rate. For example, at primary, 22% of unauthorised absences came from 2% of pupils and, at secondary, 48% came from 7% of pupils.

In fact, the disparity between primary and secondary in the number of frequent absentees was the main driver of unauthorised absence rates being higher at secondary than primary. These pupils were disproportionately likely to be disadvantaged, and to have an EHCP.

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