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Calderbank Offer Letter Builder

Led by Diellza Nika Hyseni and Mentor Nika · Updated 24 October 2026

Make a Calderbank offer: a letter offering to settle a claim, “without prejudice save as to costs”, in your own terms, ready for your letterhead. With what the court or tribunal can do with it, and where it carries no weight. From DMD Costs, law costs draftsmen in Westhoughton, Bolton.

  • Free, with no sign-up
  • Word download
  • Every rule sourced
  • Nothing leaves your browser

Give the claim and your own terms. The letter on the right updates as you type and downloads as a Word file. The builder never suggests what to offer, and it makes offers on a claim only, never on costs.

The dispute

The builder applies CPR 21.10, 27, 36, 44, 45.1 and 46.14, PD 47, FPR 28.3, PD 28A, the Employment Tribunal Procedure Rules 2024, s.203 of the Employment Rights Act 1996 and the cases named, as they stood on 24 October 2026. The terms are yours; whether to make an offer, and what to offer, are for you and your client. It is a guide, not legal advice.

Key points

  • DMD Costs’ Calderbank offer letter builder is a free online tool that drafts a written offer to settle a claim, marked “without prejudice save as to costs”, in your own terms, as a Word document.
  • It is completely free, with no sign-up, and runs in your browser; nothing you type is sent to DMD Costs. It makes offers on a claim only, never on costs, and never suggests what to offer.
  • A Calderbank offer cannot be shown to the judge while the claim is decided, but can be when costs are: the name comes from Calderbank v Calderbank [1976] Fam 93, and Cutts v Head [1984] Ch 290 applied it in civil litigation.
  • In civil claims the court has regard to any admissible offer to settle that does not carry Part 36 costs consequences when it decides costs (CPR 44.2(4)(c)), but nothing follows automatically: an offer not made in accordance with rule 36.5 does not have Part 36’s consequences (CPR 36.2(2)).
  • Part 36’s test that a result “better in money terms by any amount, however small” beats an offer (CPR 36.17(2)) is not read into Part 44: a Calderbank offer is unlikely to count for much if the other side did significantly better (Coward v Phaestos Ltd [2014] EWCA Civ 1256 at [98] and [102]).
  • A letter marked only “without prejudice” generally cannot be shown to the court, even on costs, unless both parties agree (Reed Executive plc v Reed Business Information Ltd [2004] EWCA Civ 887 at [19] and [21]).
  • In fast track, intermediate track and noise-induced hearing loss claims, the court can award only the Part 45 fixed costs even where costs are agreed, unless both sides expressly agree otherwise (CPR 45.1(3)), so the letter’s costs term covers fixed costs where Part 45 fixes them.
  • In financial remedy proceedings, including variation and interim variation applications, an offer that is not open cannot be used on costs (FPR 28.3(8); PD 28A para 4.2(a)); once a claim is allocated to the small claims track Part 36 does not apply (CPR 27.2(1)(g)); in employment tribunals, rejecting an offer counts only if the rejection was unreasonable (Sud v Ealing LBC [2013] EWCA Civ 949 at [82]), and a settlement needs a COT3 or a settlement agreement (Employment Rights Act 1996 s.203).

How to use the Calderbank offer letter builder

  1. Choose the court or tribunal. A civil claim, a small claim, a family case outside financial remedy proceedings, or an employment tribunal claim; and which side makes the offer.
  2. Say who writes, and to whom. A firm for its client or the party itself, to the other side’s solicitors or to the other party, with the names and the claim number.
  3. Give your terms. The sum, whether it includes interest and when it is paid, and any other terms in your own words, such as repairs; and whether it settles the whole claim, part of it or one issue.
  4. Choose costs and a time limit. How costs are dealt with if it is accepted, from a fixed menu that follows the offer’s scope and covers Part 45 fixed costs, and how many days it stays open.
  5. Check and download. Read the checks and what the offer can do in your forum, then download the letter as a Word file to put on your letterhead.

What a Calderbank offer is

Offers made expressly “without prejudice save as to costs” are admissible on the question of costs: that was decided in the family context in Calderbank v Calderbank [1976] Fam 93, and in general civil litigation in Cutts v Head [1984] Ch 290, and such offers go by the name Calderbank offers (Reed Executive plc v Reed Business Information Ltd [2004] EWCA Civ 887 at [20]). The words matter: a letter marked only “without prejudice” generally cannot be used even on costs, unless both parties agree ([19] and [21]).

In civil claims

When it decides what order to make about costs, the court has regard to all the circumstances, including “any admissible offer to settle made by a party which is drawn to the court’s attention, and which is not an offer to which costs consequences under Part 36 apply” (CPR 44.2(4)(c)). It can then make, for example, an order for costs from or until a certain date only (CPR 44.2(6)(c)), and it looks at conduct before as well as during the proceedings (CPR 44.2(5)(a)). Part 36 is a self-contained code: an offer not made in accordance with rule 36.5 does not have its consequences (CPR 36.2(2)), and there is no warrant for reading its “better in money terms by any amount, however small” test into Part 44 (Coward v Phaestos Ltd [2014] EWCA Civ 1256 at [98] and [102]). If you want the automatic consequences, make a Part 36 offer: the N242A builder fills in the form, and the Part 36 calculator works out what follows.

In a claim that would normally be or is allocated to the fast track or the intermediate track, or a noise-induced hearing loss claim within Section VIII, the court can award only the Part 45 fixed costs even where costs are agreed, unless both sides have expressly agreed that Part 45 does not apply (CPR 45.1(3), 45.43, 45.49 and 45.52). So the letter’s costs term pays the fixed costs where Part 45 fixes them, and reasonable costs assessed on the standard basis otherwise. For an offer on part of a claim or one issue, the costs term covers only that part or issue, or leaves its costs to the court, and the letter says it does not deal with the costs of the rest.

Small claims, family cases and tribunals

In the small claims track Part 36 does not apply (CPR 27.2(1)(g)), and rejecting an offer is not of itself unreasonable behaviour, though the court may take it into account (CPR 27.14(3)). In financial remedy proceedings, including variation and interim variation applications, an offer that is not open is not admissible at any stage, save that offers are filed for the FDR (FPR 28.3(8) and 9.17; PD 28A para 4.2(a)), so the builder does not make one there; but in a Schedule 1 claim or most other interim applications, rule 28.3 does not apply and a Calderbank offer counts (PD 28A paras 4.2 and 4.7), with any agreed terms put to the court as a consent order. In an employment tribunal, the civil consequences do not apply: rejecting an offer is relevant only if the tribunal first finds the rejection unreasonable (Sud v Ealing LBC [2013] EWCA Civ 949 at [82]). And a promise not to bring or continue most statutory employment claims is void unless it is made through Acas (a COT3) or in a settlement agreement that meets the statutory conditions (Employment Rights Act 1996 s.203; Equality Act 2010 ss.144 and 147), so the letter says the settlement will be recorded in one.

How long it stays open

A Calderbank offer is governed by contract, with no direct read-across from Part 36 (MEF v St George’s Healthcare NHS Trust [2020] EWHC 1300 (QB) at [35]). An offer with no time limit stayed open there and was validly accepted during a detailed assessment hearing ([37] and [47]); the offeror could have put a time limit on it, or withdrawn it ([43]). At common law a rejected offer cannot be accepted ([25]), so the letter says a rejection or counter-offer will not end it. It states a time limit, moved to the next working day if it would end at a weekend or on a bank holiday, says the offer can be withdrawn in writing before acceptance, and asks for a written acceptance that reaches the offeror in time.

Sources

Frequently asked questions

A written offer to settle marked “without prejudice save as to costs”. It cannot be shown to the judge while the claim itself is decided, but it can be put before the court when costs are decided. The name comes from Calderbank v Calderbank [1976] Fam 93, a matrimonial case; Cutts v Head [1984] Ch 290 confirmed the practice in civil litigation (Reed Executive plc v Reed Business Information Ltd [2004] EWCA Civ 887 at [20]).
A Part 36 offer must comply with CPR 36.5: in writing, stated to be made under Part 36, with a relevant period of at least 21 days. If it is not beaten when judgment is entered, the consequences in CPR 36.17 follow unless the court considers them unjust: for a claimant who does at least as well as its own offer, interest of up to 10% above base rate, indemnity costs and an additional amount (in fixed costs cases, an extra 35% of the difference in fixed costs instead: CPR 36.24). A Calderbank offer has none of those consequences (CPR 36.2(2)); the court weighs it within its discretion on costs (CPR 44.2(4)(c)).
The court decides; nothing is automatic. It weighs the offer with all the circumstances, including conduct and partial success (CPR 44.2(4)), and may, for example, order costs from or until a date (CPR 44.2(6)(c)). Part 36’s “better in money terms by any amount, however small” test (CPR 36.17(2)) is not read into Part 44, and an offer is unlikely to count for much if the other side did significantly better (Coward v Phaestos Ltd [2014] EWCA Civ 1256 at [98] and [102]).
Not on costs. In financial remedy proceedings within FPR 28.3, an offer that is not open is not admissible at any stage, except that offers go to the FDR judge under FPR 9.17 (FPR 28.3(8); PD 28A para 4.3). The court looks at open offers instead (FPR 28.3(7)(b)), and each party must make an open proposal (FPR 9.27A). That includes variation and interim variation applications. Schedule 1 Children Act claims and most other interim applications fall outside rule 28.3 (PD 28A para 4.2), and there a Calderbank offer counts (PD 28A para 4.7); agreed terms then go to the court as a consent order.
Once a claim is allocated to the small claims track, Part 36 does not apply (CPR 27.1(1) and 27.2(1)(g)), and the costs that can be recovered are limited (CPR 27.14). Rejecting an offer is not of itself unreasonable behaviour, but the court may take it into account when deciding whether a party behaved unreasonably (CPR 27.14(3)).
Only indirectly. The costs consequences of Calderbank offers in civil courts do not apply in the employment tribunal; the tribunal must first find that rejecting the offer was unreasonable, and failing to beat it is not enough by itself (Sud v Ealing LBC [2013] EWCA Civ 949 at [82]). The tribunal must consider a costs order where a party acted unreasonably (Employment Tribunal Procedure Rules 2024, r.74(2)). And most statutory employment claims can be settled only through Acas (a COT3) or by a settlement agreement that meets the statutory conditions (Employment Rights Act 1996 s.203; Equality Act 2010 ss.144 and 147), so the letter says the settlement will be recorded in one.
As long as its terms say: it is governed by contract, not by Part 36 (MEF v St George’s Healthcare NHS Trust [2020] EWHC 1300 (QB) at [35]). An offer with no time limit lasts for a reasonable time: in MEF one was validly accepted during a detailed assessment hearing ([32], [37], [47]). At common law a rejected offer cannot be accepted ([25]), unlike a Part 36 offer. The offeror can put a time limit on it, or withdraw it before it is accepted ([43]). The builder states a time limit unless you leave it blank, says a rejection or counter-offer will not end the offer, and asks for a written acceptance that reaches the offeror in time.
No. Offers on a bill of costs are part of the costs negotiation we do for a fee. In detailed assessment, the paying party must say in an open letter with its points of dispute what sum, if any, it offers (PD 47 para 8.3), and an offer should say whether it includes the cost of preparing the bill and VAT and, if it is not a Part 36 offer, interest, or it is treated as including them (PD 47 para 19).

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