---
title: "Check a Calderbank letter separately from a New South Wales rule 20.26 offer"
url: "https://ailawframework.com/practice/commercial-litigation-and-dispute-resolution/check-a-calderbank-letter-against-the-factors-for-an-indemnity-costs-app/new-south-wales"
type: "task_jurisdiction_version"
site: "AI Law Framework"
id: "A5-LT20261023-2-NSW"
practice_area: "Commercial Litigation & Dispute Resolution"
tier: "yellow"
lawyer_review: "required"
jurisdictions: ["NSW"]
last_reviewed: "2026-10-25"
---

# Check a Calderbank letter separately from a New South Wales rule 20.26 offer

> From the letter, list the offer, how long it was open, whether it is inclusive of costs, and whether it is marked without prejudice except as to costs. The tool does not decide whether rejection was unreasonable.

Canonical page: https://ailawframework.com/practice/commercial-litigation-and-dispute-resolution/check-a-calderbank-letter-against-the-factors-for-an-indemnity-costs-app/new-south-wales  
Last reviewed: 2026-10-25

Site index for agents: https://ailawframework.com/llms.txt

## Key facts

| Fact | Value |
| --- | --- |
| Practice area | [Commercial Litigation & Dispute Resolution](https://ailawframework.com/practice/commercial-litigation-and-dispute-resolution.md) |
| Human involvement | Yellow: Lawyer and AI draft together |
| How AI is used | From the letter, list the offer, how long it was open, whether it is inclusive of costs, and whether it is marked without prejudice except as to costs. The tool does not decide whether rejection was unreasonable. |
| What the lawyer must review | The lawyer decides whether rejection was unreasonable. A rule 20.26 offer must not be inclusive of costs, subject to subrule (3). If that formal offer is made two months or more before the trial, the closing date is at least 28 days. Use the six factors for the letter. They do not apply the rule 42.14 timetable. |
| Written for | New South Wales |
| Applies to | [Check a Calderbank letter against the factors for an indemnity costs application](https://ailawframework.com/practice/commercial-litigation-and-dispute-resolution/check-a-calderbank-letter-against-the-factors-for-an-indemnity-costs-app.md) |

## Checking plan

**Verify against sources**

The lawyer judges the Calderbank letter. The tool contrasts it with rule 20.26.

- What the AI does: From the letter, list the offer, how long it was open, whether it is inclusive of costs, and whether it is marked without prejudice except as to costs. The tool does not decide whether rejection was unreasonable.
- What the lawyer does: Decide whether rejection was unreasonable, and whether the document is a formal offer.
- Who reviews: Lawyer competent in this practice area
- Basis: Checked against the linked sources on 23 October 2026. Confirm the current instrument before reliance.

## Checks the lawyer makes

1. The article describes a Calderbank letter as marked without prejudice except as to costs. It may be inclusive of costs and open for a short time. Indemnity depends on whether rejection was unreasonable.
2. The six matters from the article's account of Hazeldene at [25] are the stage, the time allowed, the extent of the compromise, the prospects at the date of the offer, the clarity of the terms, and whether an indemnity application was foreshadowed.
3. A formal offer under rule 20.26 must state that it is made under the rules and must not be inclusive of costs, subject to subrule (3).
4. A notice that purports to exclude rule 42.14 or rule 42.15 has no effect. That rule is about a formal offer, not about the letter.

## Notes

- Supreme Court Practice Note SC GEN 23, commenced on 3 February 2025, prohibits generative AI from generating evidentiary content, and requires prior leave before it is used to draft an expert report.
- Rules 42.13A and 42.15A appear in the article and were not opened on the rules site. They are not used here. The Hazeldene judgment itself was not opened.

## Practical guide

Jurisdiction: A New South Wales proceeding in which a Calderbank letter is used on costs, contrasted with an offer under rule 20.26

**Deliverable**: A factor-by-factor note on the letter.

**Inputs**

- The letter
- Whether it is inclusive of costs
- Whether it states that it is made under the rules

**Example**: Illustrative example: The letter is inclusive of costs and open for a week. The note does not treat it as a rule 20.26 offer. The lawyer decides whether the week was long enough.

**Stop and escalate when**

- The document states that it is made under the rules. Check rule 20.26 instead.
- The tool is asked to decide that rejection was unreasonable.

Checked 2026-10-23.

## Sources

- [Law Society Journal, settlement offers and indemnity costs (4 October 2022)](https://lsj.com.au/articles/what-is-a-calderbank-offer-settlement-offers-and-indemnity-costs/) (checked 2026-10-23)
- [Uniform Civil Procedure Rules 2005 (NSW) r 20.26](https://www.austlii.edu.au/au/legis/nsw/consol_reg/ucpr2005305/s20.26.html) (checked 2026-10-23)
- [Supreme Court of NSW, Practice Note SC GEN 23](https://supremecourt.nsw.gov.au/documents/Practice-and-Procedure/Practice-Notes/general/current/PN_SC_Gen_23.pdf) (checked 2026-10-23)

## Forms and precedents for this task

| Form or precedent | Kind | AI level | Summary |
| --- | --- | --- | --- |
| [Reply to a Calderbank offer in a personal injury claim](https://ailawframework.com/precedents/personal-injury-and-compensation/reply-to-calderbank-offer.md) | Letter | Yellow | A reply to a Calderbank offer in a Victorian, Queensland or New South Wales personal injury claim. It identifies unclear terms and the time allowed, and in Victoria it uses the Hazeldene list only. |

Signed-in accounts can read the full text of each one.

*Practice guidance for planning and review. Confirm current primary sources and the requirements of the actual matter. This is general information, not legal advice.*