A costs dispute can only be dealt with under the dispute procedure where the amount of costs does not exceed $25,000. Before the dispute can be heard, the person making the complaint must lodge the amount of costs in dispute with the Commissioner, unless:

The Commissioner must first attempt to settle the dispute, but if unable to do so may refer the matter for mediation by a mediator appointed from a panel (s.4.3.8). If the mediator is unable to resolve the dispute, either party may refer the matter for a hearing by the VCAT, who will make a determination on the dispute.

The Tribunal may order (under s.4.3.17) that:

Disputes over costs in excess of $25,000 are handled by a more formal process before the Taxing Master (an officer of the Supreme Court appointed to determine bills of costs). Before a lawyer's bill can be challenged, it must be in a particular form.

Usually, the bill delivered to the client will not list each item of work performed, even if the lawyer's costs have been calculated according to the applicable scale (see: "Lawyers' costs", above). Instead, it will briefly list the items of work performed and state a single amount as "professional costs". This can make it difficult to work out whether the correct amount has been charged.

It may be advisable for the client to request a detailed bill, known as a bill in "taxable form", so that they can check whether the correct scale has been applied. The detailed bill must be delivered within 21 days of the request, and without additional cost to the client (s.3.4.36).

A bill of costs is in taxable form if it gives itemised details of each service performed and the appropriate scale item charged, and if the professional charges and disbursement are entered in separate columns (Supreme Court Rules, Order 65, r.20).

A client who feels that the bill is too high can complain to the Commissioner. However, unless the disputes procedure discussed above applies, they may have to have the bill assessed (or checked) by the Taxing Master. Application to the Taxing Master to have the bill assessed must be made within 60 days after the bill was made or the costs paid. If the Taxing Master decides that any charges are unreasonable, these will be deducted from the amount the client must pay. However, unless at least one-sixth of the bill is taken off (and it is possible for the Taxing Master to add to the bill) the client will have to pay an extra sum to the original lawyer for the costs of having the bill taxed. This includes the costs of attending the Taxing Master's hearing. Assessment is not commonly used by individual clients in these situations.

If the dispute concerns financial loss, the VCAT may award compensation of up to $25,000 (s.4.3.17 LP Act). These disputes are dealt with in the same way as costs disputes: the Commissioner attempts to settle the dispute, and may appoint a mediator. If the attempt to settle or the mediation fails, the matter can be referred by either party for a hearing by the VCAT.

Normally, a lawyer must not commence legal proceedings to recover legal costs from a person until at least 65 days after the lawyer has given a bill of costs to the person (s.3.4.33 LP Act). The bill must be signed by an appropriate person and may be in a lump sum form or itemised form (s.3.4.34).