Accuracy is fundamental in litigation. Court orders and judgments are intended to record precisely what the Court has decided. However, judges, court staff and legal professionals are all human, and occasional drafting errors can occur.

This is where the Slip Rule, contained within CPR Part 40.12, becomes important.

A recent issue arising in practice prompted a closer look at this rule and reinforced the importance of understanding when it should and should not be used.

What is the Slip Rule?

The Slip Rule is set out in CPR 40.12, which provides:

(1) The court may at any time correct an accidental slip or omission in a judgment or order.
(2) A party may apply for a correction without notice.

In simple terms, the Slip Rule allows the Court to correct minor, accidental errors in judgments or orders.

These errors typically include:

• Typographical mistakes

• Incorrect party names

• Wrong dates

• Clerical omissions

The key point is that the Slip Rule does not change the substance of the Court’s decision. It exists purely to ensure that the written order accurately reflects what the Court intended.

Importantly, the phrase “at any time” means there is no strict time limit for correcting such errors – provided the correction is genuinely accidental and does not alter the original decision.

When Does It Become Necessary to Use the Slip Rule?

Interestingly, the matter that brought this Practice Direction to mind was actually an example of when it was not necessary to invoke the Slip Rule.

In this case, we had been instructed by an authorised person to assist in litigation and were reviewing a consent order drafted by the Claimant’s representatives. The order stated:

“The deadline for the Defendant to file and serve the Reply to Defence and for both Parties to file and serve Directions Questionnaires is…”

As practitioners will immediately recognise, a Defendant who has filed and served a Defence does not go on to file a Reply to Defence, that is the responsibility of the Claimant.

The error was obvious. Yet it had been missed by experienced professionals and even by the Court when sealing the order.

Despite the drafting mistake, both parties clearly understood their respective responsibilities. The Claimant proceeded to file the Reply to Defence as appropriate, and the case progressed without issue. As such, there was no need to exercise the Slip Rule.

When Should the Slip Rule Be Used?

There are, however, circumstances where the Slip Rule is essential.

If a mistake in an order:

• Adversely affects the accuracy of the Court record

• Creates ambiguity about the parties’ obligations

• Impacts a party’s procedural position

then it becomes necessary to apply CPR 40.12 to correct the error.

The purpose is not to revisit arguments or alter substantive outcomes. Instead, it is to ensure the order properly reflects what was intended.

How to Apply CPR 40.12

If you identify an accidental slip in a judgment or order, the process is generally straightforward.

A simple email to the Court:

• Identifying the error

• Referring expressly to CPR 40.12

• Explaining why the mistake is accidental

is usually sufficient for the matter to be referred to a judge for correction.

The rule allows an application to be made without notice, meaning it does not necessarily require a formal application hearing.

Why the Slip Rule Matters

The Slip Rule is a practical and efficient mechanism for maintaining accuracy in legal proceedings. It prevents minor errors from causing confusion or procedural complications, without reopening substantive issues.

While straightforward, it remains an often overlooked tool in practice. Careful drafting and prompt review of Court orders remain essential, but when mistakes do arise, CPR 40.12 provides a clear and effective solution.

This blog has been written by Millie Stewart, Legal Assistant at White Collar Legal. Millie is a third-year law student currently studying Law and Criminology at Edge Hill University.