A bill of costs is an itemized list what expenses a prevailing party in a lawsuit

Lawsuit

A lawsuit or "suit in law" is a civil action brought in a court of law in which a plaintiff, a party who claims to have incurred loss as a result of a defendant's actions, demands a legal or equitable remedy. The defendant is required to respond to the plaintiff's complaint...

 or action needs to pay for services procured from a lawyer. It can have varying levels of detail, and should describe the nature of the work done by the lawyer for the client, and any other expenses incurred. Recoverable costs vary by jurisdiction, but often include copying fees, filing fees, travel expenses, court reporter fees, and electronic legal research costs.(example checklist of expenses recoverable in a bill of costs)

In some cases, particularly those in which attorney's fees are part of the relief

Legal remedy

A legal remedy is the means with which a court of law, usually in the exercise of civil law jurisdiction, enforces a right, imposes a penalty, or makes some other court order to impose its will....

 demanded by the plaintiff

Plaintiff

A plaintiff , also known as a claimant or complainant, is the term used in some jurisdictions for the party who initiates a lawsuit before a court...

, a bill of costs may be submitted to the court

Court

A court is a form of tribunal, often a governmental institution, with the authority to adjudicate legal disputes between parties and carry out the administration of justice in civil, criminal, and administrative matters in accordance with the rule of law...

, in order to determine how much of the prevailing party's costs the losing party must pay.