Opinion
LILLIE, Acting P. J.Diane Shank appeals from judgment denying her petition for relief (Gov. Code, § 946.6) from the provisions of section 945.4, Government Code, requiring that a written claim be presented to respondent County of Los Angeles before an action may be brought against it.
Shank allegedly sustained personal injuries on July 24, 1980, when she slipped and fell on the premises of the Los Angeles County Olive View Medical Center (Olive View) as she was leaving a doctor’s office there. On August 13, 1980, Shank’s attorney sent a letter to Olive View explaining the circumstances of the accident and requesting that the hospital forward the letter to its insurance carrier. In a letter dated August 15, 1980, the hospital responded by indicating that it was “unable to identify this patient. ” The letter was written on stationery which bore the letterhead “Los Angeles County-Olive View Medical Center” in block letters three-sixteenths inch high; to the left of this inscription appeared the county seal with the words “Department of Health Services” beneath it. On August 20, 1980, Shank’s attorney sent another letter to Olive View stating that his client was not a patient but a claimant and again requesting that the letter be turned over to the hospital’s insurance carrier. On September 28,1980, the attorney sent a third letter to Olive View indicating that he had not heard from its insurance carrier. On December 9, 1980, the hospital wrote to Shank’s attorney stating that inasmuch as the incident occurred on county premises, a complaint should be filed with the clerk of the board of supervisors. On December 23,1980, Shank presented to the county a written application for leave to file a late claim for damages for personal injuries sustained in her slip- and-fall accident at the hospital. The application was denied on February 5, 1981. Shank then filed the within petition setting forth the above facts and alleging that the reason for the delay in presenting the claim was mistake, inadvertence, surprise or excusable neglect. In his declaration in support of the petition Shank’s attorney stated that he was not informed that Olive View is a “county entity” until he received the letter of December 9, 1980, which was more than 100 days after accrual of Shank’s cause of action for personal injuries.
Government Code section 911.21 requires that a claim relating to a cause of action for personal injury be presented to a public entity within 100 days after *156accrual of the cause of action. When such a claim has not been timely presented, section 911.4 permits written application to the public entity for leave to file a late claim. If the public entity denies such application, section 946.6, subdivision (a), authorizes a petition to the superior court for relief from the provisions of section 945.4 requiring the presentation of a written claim to a public entity before an action for damages may be brought against it. Such relief shall be granted “if the court finds that the application . . . under Section 911.4 was made within a reasonable time not to exceed [one year after the accrual of the cause of action] . . . and that . . . [t]he failure to present the claim was through mistake, inadvertence, surprise or excusable neglect. . . .” (§ 946.6, subd. (c).)
The granting or denial of a petition for relief under section 946.6 rests within the discretion of the trial court and its determination will not be disturbed on appeal except for abuse of that discretion. (Rivera v. City of Carson (1981) 117 Cal.App.3d 718, 725 [173 Cal.Rptr. 4]; Roberts v. State of California (1974) 39 Cal.App.3d 844, 847 [114 Cal.Rptr. 518].) It is true that an appellate court more carefully scans the denial than the allowance of such relief to the end that wherever possible cases may be heard on their merits. (Viles v. State of California (1967) 66 Cal.2d 24, 29 [56 Cal.Rptr. 666, 423 P.2d 818].) Nevertheless, we cannot arbitrarily substitute our judgment for that of the trial court. (Bennett v. City of Los Angeles (1970) 12 Cal.App.3d 116, 120 [90 Cal.Rptr. 479].) “Unless, ultimately, each case of this nature is to be decided by the Court of Appeal as if no trial court had ever acted on the petition, we must be careful to preserve the area of the superior court’s discretion, and we must do this in fact, as well as in words.” (Ibid.)
Before a court may relieve a potential plaintiff from the claim requirement of section 945.4, the plaintiff must demonstrate by a preponderance of the evidence that his application to the public entity for leave to file a late claim was presented within a reasonable time, and that the failure to file a timely claim was due to mistake, inadvertence, surprise or excusable neglect.2 (Rivera v. City of Carson, supra, 117 Cal.App.3d 718, 723; El Dorado Irrigation Dist. v. Superior Court (1979) 98 Cal.App.3d 57, 62 [159 Cal.Rptr. 267].) The showing required of a petitioner seeking relief because of mistake, inadvertence, surprise or excusable neglect under section 946.6 is the same as required under Code of Civil Procedure section 473 for relieving a party from a default judgment. (Viles v. State of California, supra, 66 Cal.2d 24, 29.) In the *157cases applying Code of Civil Procedure section 473, it is not every mistake that will excuse a default, the determining factor being the reasonableness of the misconception. (Black v. County of Los Angeles (1970) 12 Cal.App.3d 670, 675 [91 Cal.Rptr. 104].) This principle likewise applies to excusable neglect, which is “ ‘that neglect which might have been the act of a reasonably prudent person under the same circumstances.’ ” (Tammen v. County of San Diego (1967) 66 Cal.2d 468, 476 [58 Cal.Rptr. 249, 426 P.2d 753].) Petitioner presented evidence showing that until her attorney received Olive View’s letter of December 9, 1980, he was unaware of the hospital’s affiliation with the county and the consequent necessity of filing a claim. However, a petitioner or his attorney must show more than that they did not discover a fact until too late; they must establish hat in the use of reasonable diligence they failed to discover it. (City of Fresno v. Superior Court (1980) 104 Cal.App.3d 25, 32 [163 Cal.Rptr. 807]; Black v. County of Los Angeles, supra, 12 Cal.App.3d 670, 677.) There is a total absence of evidence that petitioner or her attorney exercised reasonable diligence (or any diligence) in an effort to ascertain the public status of Olive View. Such negligence was compounded when, with more than two months remaining in which to present a timely claim, the attorney received the hospital’s letter of August 15,. 1980, and failed to note the letterhead thereon which clearly identified Olive View as a county hospital.3 The trial court properly could find that such conduct was not that of a reasonably prudent person under similar circumstances, and thus constituted inexcusable neglect. “It is not the purpose of remedial statutes to grant relief from defaults which are the result of inexcusable neglect of parties or their attorneys in the performance of the latter’s obligation to their clients.” (Tammen v. County of San Diego, supra, 66 Cal.2d 468, 478.) We perceive no abuse of discretion in the trial court’s denial of the petition.
Petitioner argues that such denial was an abuse of discretion because the three letters which her attorney sent to the hospital within 100 days after accrual of her cause of action constituted substantial compliance with the claim filing requirement in that such letters apprised the county of petitioner’s claim against it. We do not agree. “It is well settled that claims statutes must be satisfied even in face of the public entity’s actual knowledge of the circumstances surrounding the claim. Such knowledge—standing alone—constitutes neither substantial compliance nor basis for estoppel.” (City of San Jose v. Superior Court (1974) 12 Cal.3d 447, 455 [115 Cal.Rptr. 797, 525 P.2d 701, 76 A.L.R.3d 1223].) *158Furthermore, in this proceeding for relief under section 946.6 the issue of substantial compliance was not before the trial court and therefore is irrelevant in determining on appeal whether the court abused its discretion in denying relief. (See Toscano v. County of Los Angeles (1979) 92 Cal.App.3d 775, 782-783 [155 Cal.Rptr. 146].) “An argument that one filed a timely claim is inconsistent with a petition for relief under section 946.6, since such petition necessarily follows the denial of an application for leave to file a late claim. Again, we conclude that the issue of substantial compliance with sections 911.2 and 945.4 was outside the scope of the superior court proceeding, and that no abuse of discretion could be founded thereon.” (Toscano, supra, 92 Cal.App.3d at p. 783.)
Petitioner further contends that the county should be estopped to assert her noncompliance with the claim filing requirement because the county did not inform petitioner or her attorney that Olive View is a public facility until after expiration of the 100-day period within which to file a claim. The contention lacks merit. Less than one month after accrual of petitioner’s cause of action, her attorney was so informed upon receipt of the hospital’s letter bearing a letterhead which clearly identified Olive View as a county hospital (see § 7530). In any event, “estoppel requires some affirmative representation or acts by the public agency or its representatives inducing reliance by the claimant.” (Tammen v. County of San Diego, supra, 66 Cal.2d 468, 480; italics added.) It has also been held that estoppel is available where the complaint alleges facts which, if true, would establish that the government acted in an unconscionable manner. (Fredrichsen v. City of Lakewood (1971) 6 Cal.3d 353, 359 [99 Cal.Rptr. 13, 491 P.2d 805].) Petitioner did not allege, nor does the record show, that her failure to file a timely claim was occasioned by any misconduct, concealment or other unconscionable act on the part of Olive View. The dissenting opinion suggests that Olive View was at fault in not having informed plaintiff of the necessity of filing a claim until after expiration of the 100-day period. The burden was upon plaintiff to ascertain the public status of the hospital and the consequent necessity of filing a claim; Olive View was not required to tell plaintiff to file a claim (see McGranahan v. Rio Vista etc. Sch. Dist. (1964) 224 Cal.App.3d 624, 630 [36 Cal.Rptr. 798]; Cruise v. City & County of San Francisco (1951) 101 Cal.App.2d 558, 564 [225 P.2d 988].) That it eventually did so does not provide a basis for estoppel in view of the fact that it did not previously tell plaintiff anything that would reasonably tend to mislead her regarding the necessity of filing a claim, but on the contrary promptly sent plaintiff a letter which clearly indicated that Olive View is a county facility.
The dissent cites Flores v. Board of Supervisors (1970) 13 Cal.App.3d 480 [91 Cal.Rptr. 717, 55 A.L.R.3d 925], in support of the proposition that lack of a showing of prejudice to the county because of plaintiff’s delay in filing her claim may be considered in determining whether plaintiff should be *159relieved of the claim-filing requirement. Flores ignores the rule that a public entity has no burden to establish prejudice until the plaintiff has satisfied the trial court that his failure to file a timely claim was due to mistake, inadvertence, surprise or excusable neglect. (Tammen v. County of San Diego, supra, 66 Cal.2d 468, 478; Rivera v. City of Carson, supra, 117 Cal.App.3d 718, 726; Hasty v. County of Los Angeles (1976) 61 Cal.App.3d 623, 627 [131 Cal.Rptr. 347]; Black v. County of Los Angeles, supra, 12 Cal.App.3d 670, 677-678.)
The judgment is affirmed.
Reese, J.,* concurred.
Unless otherwise indicated, all statutory references henceforth are to the Government Code.
The record herein indicates that the trial court denied the petition on the ground that failure to present a claim within the 100-day period was the result of inexcusable neglect, and thus did not reach the question whether the application for leave to present a late claim was made within a reasonable time. We likewise ignore that issue inasmuch as the application, filed two weeks after petitioner first learned of the hospital’s public status, arguably was made within a reasonable time after discovery of that fact.
The content of the hospital’s letterhead complied with section 7530 which provides in pertinent part: “All public agencies, public entities, districts, cities, counties, and cities and counties shall, when being identified by such entity for any purpose, be identified as a public agency, public entity, district, city, county, or city and county, whichever is appropriate.
“The requirements of tins section shall be deemed satisfied if the words ‘state,’ ‘public agency,’ ‘public entity,’ ‘district,’ ‘city,’ ‘county’ or ‘city and county,’ whichever is appropriate, appears on all letterhead stationery of such public agency, public entity, district, city, county, or city and county . . . .”
Assigned by the Chairperson of the Judicial Council.