Costs Lawyer Explained: The Qualification Route and What the Role Covers

Legal costs is one of the most specialised, and least understood, corners of the legal profession, and the practitioners who work in it full time — costs lawyers — hold their own distinct qualification and regulatory status, separate from solicitors and barristers, built specifically around the technical demands of assessing and disputing legal costs.

What a costs lawyer does

A costs lawyer specialises in legal costs matters: preparing and negotiating bills of costs, advising on costs budgeting under the Civil Procedure Rules, conducting detailed assessment proceedings, and representing parties in costs disputes both between opposing parties and, in some cases, between a solicitor and their own client over billing. This connects closely to the wider costs and litigation funding landscape covered in our guide to Part 36 offers and costs recovery, where getting the underlying costs position right is often as commercially significant as the litigation outcome itself.

The Costs Lawyer Professional Qualification

The standard route to becoming a costs lawyer is the Costs Lawyer Professional Qualification (CLPQ), a modular training course typically completed over around two years, combining theoretical study with practical assessment. Trainee costs lawyers need to pass both the academic and practical components before qualifying, and candidates already holding related qualifications or with relevant prior experience may be granted exemptions that shorten the overall timeline. Trainees working towards the CLPQ often find the practical assessment component the more demanding of the two, since it requires applying costs rules to realistic, messy scenarios rather than simply recalling the underlying Civil Procedure Rules provisions from memory.

Rights and authorisation

Once qualified and authorised, a costs lawyer holds rights of audience in costs proceedings and the authority to conduct litigation in costs matters — a scope of practice comparable in that specific area to a solicitor's, without needing to qualify as a solicitor through the SQE or an equivalent route. Costs lawyers are also authorised to administer oaths and take affidavits under the Courts and Legal Services Act 1990, a power that supports the practical demands of preparing and swearing costs-related documents.

Where costs lawyers typically work

Costs lawyers work across litigation costs disputes, private client billing and fee disputes, and the assessment of publicly funded (legal aid) cases, giving them a role that spans commercial litigation support, professional risk management for law firms managing their own billing disputes, and the more specialist end of legal aid cost assessment work. Publicly funded work carries its own particular costs assessment challenges, since legal aid rates and assessment criteria differ from the commercial costs recovery rules that apply between paying parties in civil litigation.

Why firms increasingly rely on dedicated costs specialists

As costs budgeting and costs management have become a more prominent, more heavily scrutinised part of civil litigation, firms have increasingly brought in dedicated costs lawyers rather than relying solely on fee earners to handle costs work alongside their substantive caseload. The technical, procedural nature of costs law — closely tied to the Civil Procedure Rules — rewards genuine specialisation in a way that makes a qualified costs lawyer's input valuable well beyond simply preparing a bill at the end of a case. For firms without the volume of costs work to justify an in-house costs lawyer, building a relationship with an external costs specialist for larger or contentious matters is a common middle ground.

What a costs lawyer actually does day to day

A costs lawyer's core work is assessing and challenging the legal costs generated by litigation and other legal services — drafting and checking bills of costs, negotiating settlements on costs between opposing sides, and representing clients at detailed assessment hearings where a court decides how much of the winning side's costs the losing side must pay. This sits alongside advisory work: costs lawyers routinely advise solicitors' firms on costs budgeting under the Civil Procedure Rules, on conditional fee and damages-based agreement drafting, and on costs risk before a case even starts, which is why many law firms retain a costs lawyer or costs draftsman in-house rather than instructing one only when a dispute over costs arises.

The CLSB regulates the profession and requires costs lawyers to hold professional indemnity insurance and to complete ongoing CPD to keep their practising certificate current, in the same way the SRA does for solicitors. Because the role is narrower than general litigation practice, it appeals to people who want deep specialism in one area of legal process rather than broad client-facing casework, and it's a route increasingly taken by experienced costs draftsmen who want the added rights of audience and formal recognition that come with the qualification.

Frequently asked questions

Does a costs lawyer need to be a qualified solicitor first? No — the Costs Lawyer Professional Qualification is a standalone route, separate from the SQE or the solicitor training route entirely.

How long does it take to qualify as a costs lawyer? The Costs Lawyer Professional Qualification typically takes around two years, though relevant prior experience or qualifications can reduce this.

Can a costs lawyer represent a client in court? Yes, within costs proceedings specifically — costs lawyers hold rights of audience and can conduct litigation in that specialist area.

What kind of work do costs lawyers handle? Preparing and negotiating bills of costs, costs budgeting, detailed assessment proceedings, and disputes over solicitor-client billing, among other costs-related work.