What is the burden of proving error on a motion to tax costs?

As the prevailing party, Valley had the right to recover costs. (Code Civ. Proc., 1032, subd. (b).) The burden of proof on a motion to tax costs depends upon the nature of the costs being challenged. "If the items appearing in a cost bill appear to be proper charges, the burden is on the party seeking to tax costs to show that they were not reasonable or necessary. On the other hand, if the items are properly objected to, they are put in issue and the burden of proof is on the party claiming them as costs." (Ladas v. California State Auto. Assn. (1993) 19 Cal.App.4th 761, 774.) All of the costs at issue in this appeal are specifically recoverable by statute. WWCA therefore had the burden of proving them unreasonable and/or unnecessary. We review the trial court's decision on appeal for abuse of discretion. (Bender v. County of Los Angeles (2013) 217 Cal.App.4th 968, 990.)

While WWCA raises numerous allegations as to Valley's alleged failure to provide backup documentation to support the majority of its costs, WWCA does not does not deny that the trial court conducted an in camera review of Valley's privileged supporting documentation, thereafter concluding the costs were reasonable and justifiable. WWCA did not request a statement of decision from the court, nor did it cause a transcript of the hearing on the issue to be prepared. "All intendments and presumptions are indulged to support [the trial court's order] on matters as to which the record is silent, and error must be affirmatively shown." (Denham v. Superior Court (1970) 2 Cal.3d 557, 564.) WWCA has failed to demonstrate error.