it's a numbers game with guilty pleas in nsw

In Sampson v R (2025) NSWCCA 25, the New South Wales Court of Criminal Appeal clarified a narrow but consequential issue in sentencing practice under the Crimes (Sentencing Procedure) Act 1999 (NSW) (CSPA). The Court held that mandatory guilty-plea discounts applied under s 25D of the CSPA must be calculated and expressed with mathematical precision, and cannot be rounded to even months or years after calculation.

The decision resolves uncertainty about whether courts may adjust discounted sentences for convenience or readability. It confirms that where Parliament has mandated a fixed percentage reduction, the resulting sentence must reflect the exact arithmetic outcome, even where that produces a sentence expressed in years, months and days.

Background

The appeal arose from sentencing proceedings in the District Court of New South Wales following a conviction for intentional grievous bodily harm. The offender entered a guilty plea at a stage attracting a 10 per cent discount under s 25D(2)(b)(ii) of the CSPA.

At first instance, the sentencing judge adopted a starting point of five years and six months imprisonment (66 months). A 10 per cent discount was applied for the utilitarian value of the guilty plea. The judge then referred to an additional reduction for assistance under s 22A of the CSPA and imposed a rounded head sentence of five years imprisonment, with a non-parole period of three years.

On appeal, the offender challenged the lawfulness of the sentencing methodology, arguing that the rounding of the post-discount sentence diluted the mandatory statutory reduction required by s 25D.

Statutory Framework

Section 25D of the CSPA establishes mandatory discounts for guilty pleas entered in indictable matters once an offender has been committed for trial. The provision prescribes fixed percentages tied to the timing of the plea:

• 25 per cent where the plea is entered before committal proceedings in the Local Court

• 10 per cent where the plea is entered at least 14 days before the first day of trial, or at the first available opportunity after compliance with pre-trial notice requirements

• 5 per cent in any other case

  
  

Section 25D(1) provides that these discounts are mandatory, not discretionary. Their purpose is to recognise the utilitarian value of guilty pleas, including the saving of court resources and the avoidance of contested trials.

Separately, s 22A permits sentencing discounts for assistance to authorities. Unlike s 25D, reductions under s 22A are discretionary and must be identified as distinct from any mandatory guilty-plea discount.

Issue on Appeal

The central issue before the Court of Criminal Appeal was whether a sentencing judge may round the result of a mandatory s 25D discount to an even number of months or years when expressing the final sentence.

The question was not whether rounding is permissible generally in sentencing, but whether rounding is compatible with a statutory scheme that mandates precise percentage reductions.

Decision of the Court

The Court allowed the appeal and held that mandatory guilty-plea discounts under s 25D must be applied with mathematical exactness. The resulting sentence cannot be rounded up or down after calculation, even if earlier sentencing practice tended toward neat or conventional figures.

The Court emphasised that once a starting point sentence is identified, the statutory discount produces a precise numerical outcome. That outcome must be expressed accurately, including in days where necessary, before any further discretionary reductions are considered.

By way of illustration, the Court noted that a 10 per cent discount applied to a 66-month sentence produces a reduction of 6.6 months. That reduction equates to 6 months and 18 days. The correct post-discount sentence is therefore 59.4 months, or 4 years, 11 months and 12 days. Any further reduction for assistance must be applied to that precise figure, not to a rounded approximation.

Clarification of Sentencing Methodology

The Court’s reasoning reinforces three methodological principles:

First, mandatory discounts under s 25D must be applied before any discretionary mitigation. A sentencing judge cannot blend or subsume statutory and discretionary discounts into a single rounded outcome.

Second, the application of a mandatory discount is an arithmetic exercise, not an evaluative one. Once the relevant percentage is identified, the court’s task is to calculate and record the result precisely.

Third, transparency in sentencing remarks is required. Judges must explain how the discount has been calculated and demonstrate that the offender has received the full statutory benefit.

Bench Book Update

Following the decision, the Judicial Commission of New South Wales updated its Sentencing Bench Book to reflect the authority of Sampson. The Bench Book now states that a mandatory discount under s 25D must not be rounded up or down to an even number of months.

This update amends earlier guidance that permitted rounding in certain contexts, particularly where fractional months arose from discount calculations.

Practical Significance

The decision has immediate implications for sentencing practice in New South Wales.

Sentences following guilty pleas are increasingly likely to be expressed in years, months and days rather than rounded figures. Defence practitioners must ensure that mandatory discounts are calculated precisely and articulated clearly in sentencing submissions. Prosecutors and sentencing judges must ensure that statutory entitlements are not diminished by rounding for convenience.

The decision also strengthens the ability of appellate courts to scrutinise sentencing arithmetic. Where a sentence has been rounded after the application of a mandatory discount, the error may be identifiable on the face of the sentencing remarks.

Professional Significance

The decision marks a clear shift away from informal sentencing conventions and toward strict adherence to statutory arithmetic. In doing so, it affirms transparency, consistency and fidelity to legislative design in the sentencing process.