When you win a court case in California, you may be able to get the other side to pay your court costs. To do this, you must file a "memorandum of costs" within 15 days after you receive notice that the judgment was entered, or within 180 days after the judgment, whichever comes first. This document lists all the costs you are claiming and must include a statement that the costs are accurate and were necessary for the case. If you won through a default judgment, you need to request your costs on a specific form at the time you apply for that judgment.
If you are the losing party and you disagree with the costs being claimed against you, you have 15 days after receiving the cost memorandum to file a motion to challenge those costs. If the memorandum was sent to you by mail or electronically, you may get a few extra days. When you challenge specific costs, your motion must clearly identify each cost item you are disputing and explain why you think it should not be allowed.
Both sides can agree in writing to extend these deadlines. If there is no agreement, the court can grant an extension of up to 30 days. Once the deadline to challenge costs has passed, or after any dispute is resolved, the court clerk adds the costs to the final judgment.