The High Court has recently provided guidance on the application of the slip rule. In the Family law context which applied in this case, the relevant rule was FPR Rule 29.16; in the Civil law context in which LPC Law operates, the equivalent rule is CPR 40.12, which is identical.
Mrs Justice Knowles in IC v RC  EWHC 2997 (Fam) held that the slip rule is the mechanism for the court to correct clerical errors arising from an accidental slip or omission. Reviewing the case law, Knowles J accepted that there is no definition of what constitutes a slip at common law. There must be a genuine error, and not an error of substance. Whilst the slip rule could be invoked to give effect to the court’s intention, it cannot be utilised to enable the court to have ‘second or additional thoughts’. Any mistakes of substance must be corrected by an appellate court.
The Appellant contended that the slip rule was inappropriately used in this case to vary a periodical payments order. The original order which was the subject of the appeal was drafted by the Respondent’s counsel in 2017 and varied under the slip rule in 2019. On its face, as originally drafted, it referred to payments from the ex-husband to the ex-wife ceasing upon the former’s re-marrying, rather than (as was intended by the judge) upon the latter’s re-marrying.
The Judge held that there was a good reason for the slip rule to not be time-constrained, and that its use here gave effect to the court’s original intention, which was known to the Appellant in 2017, because they had attended the hearing at which the order had been amended under the rule. The error was ‘wholly accidental and genuine’, although it was unfortunate that it had neither been detected nor corrected earlier.
The Judge further held that it was undesirable for an application under the slip rule to be ‘rendered unnecessarily complex’. She held that the interests of justice would likely prevail over other considerations in all but the most unusual of circumstances. No such exceptionally unusual circumstances arose on these facts.
The case serves as a reminder of the outer limits of the use of the slip rule. Other routes to be considered by parties aggrieved by a court’s previous order(s) include CPR 3.1(7) and appeals under CPR Part 52.