Executive Summary

This is the eighth report published since June 2023 on the Scottish Government modelling of the level of demand for prison accommodation in Scotland. It presents prison population projections for the six-month period from July to December 2025[1]. These have been produced using ‘microsimulation’ scenario modelling, which simulates prison arrivals and departures to estimate the number of individuals in prison on a given future date.

The projections are produced to support high-level decision-making, planning, and policy development. As they do not account for the full complexity of the prison population, they are not intended for use in the day-to-day management of those in prison.

Reent Developments

The previous projections were published in April 2025.

Legislation aimed at reducing the prison population was passed by the Scottish Parliament in November 2024 and enacted as the Prisoners (Early Release) (Scotland) Act in January 2025[2]. The Act changed the release point for some prisoners serving sentences of less than four years[3] from 50% to 40% of their sentence. There was no change to the release point for prisoners serving sentences for those convicted of domestic abuse or sexual offences, who continue to be released at 50%.

Those immediately impacted by the change were released in three tranches in February and March 2025. Since then, all eligible short-term prisoners have been released after serving 40% of their sentence[4]. The measures are expected to result in a sustained reduction in the short-term prisoner population, compared to what it would have been without the legislation[5].

The population projections in this publication reflect this ongoing reduction in the sentenced population by adjusting release points accordingly.

The modelling accounts for how criminal justice system activity (especially in the courts) and the flows that drive the prison population may change and uses these to estimate short-term changes in the population. The uncertainty surrounding court activity is reflected in the three scenarios based on different levels of court case conclusions: ‘low’, ‘central’, and ‘high’.

As highlighted in previous publications, the key short-term drivers of the prison population are expected to be the flows into and out of the remand and sentenced populations.

Key Points

On 1st July 2025, the overall prison population in Scotland was 8,202, and the remand and sentenced populations were 2,094 and 6,108, respectively[6].

The latest prison population projections, shown in Figure 1, indicate:

• It is likely[7] that the overall prison population will increase between 1st July 2025 and 31st December 2025.
• Across the three scenarios, it is projected that the average daily prison population could be between 7,950 and 8,750[8] in December 2025.
• It is likely that the remand population will decrease between July 2025 and December 2025. It is projected that the average daily remand population could be between 1,300 and 2,550 in December 2025.
• It is highly likely that the sentenced population will increase between July 2025 and December 2025. The average daily sentenced population could be between 6,100 and 6,850 in December 2025.
• Between April and July 2025[9], the actual prison population aligned with the higher court case conclusions scenario of the last set of projections[10].
• If the actual prison population aligns with the central scenario in these projections, then it is likely that the demand for prison spaces will rise between July and December 2025.

It is worth noting that in some past growth periods (e.g. early 2023 and early 2024) the actual population has tracked the upper end of the projection range for several weeks.

Over the coming months, remand arrivals, sentenced arrivals, and case conclusion levels will be monitored to assess which scenario the actual prison population most closely follows.

Figure 1. Prison population projections for July 2025 to December 2025. The projection range includes the overlapping 50%, 75% and 95% confidence intervals for all scenario variants given in Table 1. The actual population is shown as a series of black points.

[1] The projections start at the beginning of July 2025 because data available on cases progressing through courts only currently extends up to June 2025 (due to a time lag on receiving the processed data). As a result, the initial prison population used for the modelling is taken from 1st July 2025.