ISA 810 (Revised) — Engagements to Report on Summary Financial Statements: Complete Guide

Key Takeaways

ISA 810 (Revised) applies to engagements to report on summary financial statements derived from audited financial statements — the engagement is not an audit of the summary but a comparison against the complete accounts.
Only the same auditor who audited the complete financial statements can report on the summary — a different auditor must decline.
The opinion on the summary is binary: unmodified or adverse. There is no qualified opinion on summary financial statements because the question of consistency is itself binary.
A qualified opinion on the complete financial statements does not prevent issuing the summary report, but the qualification must be described and the summary indicated as misstated to the equivalent extent.
An adverse or disclaimer opinion on the complete financial statements prevents the auditor from expressing any opinion on the summary.
For European auditors, ISA 810 engagements remain relevant in the cooperative, mutual, and association sectors where large memberships receive summary financial information.
The requirement that only the same auditor can report on the summary ensures continuity and prevents fragmented assurance.

Why ISA 810 Matters

Many entities prepare condensed or summary versions of their audited financial statements for distribution to shareholders, employees, or the general public. These summary financial statements provide an accessible overview without the full detail of the complete accounts — but they derive from and depend upon the audited financial statements. ISA 810 (Revised) establishes the auditor's responsibilities when engaged to report on these summary financial statements, ensuring that the condensation process does not create a misleading representation of the entity's financial position.

While less frequently encountered than complete financial statement audits, ISA 810 engagements serve an important function. They protect users who rely on summary information by providing independent assurance that the condensation faithfully represents the underlying audited statements. For non-Big 4 firms across Europe, these engagements arise particularly for cooperatives, mutual organisations, associations, and entities that distribute annual summaries to large numbers of members or stakeholders.

Scope and Key Definitions

ISA 810 (Revised), effective for periods ending on or after 15 December 2016, applies to engagements to report on summary financial statements that are:

Derived from financial statements audited in accordance with ISAs
Audited by that same auditor — a different auditor cannot report on the summary financial statements

Summary financial statements: Historical financial information derived from financial statements but containing less detail than those statements, while still providing a structured representation of the entity's economic resources, obligations, or changes therein that is consistent with what the complete financial statements provide. Summary financial statements sometimes use terms such as "condensed financial statements," "abridged financial statements," or "summary annual report."

Applied criteria: The criteria applied by management in preparing the summary financial statements. These criteria may be:

Established by law or regulation — Some jurisdictions prescribe what must be included in summary accounts
Established by an authorised body — An accounting standard setter may provide requirements for summary statements
Developed by management — When no established criteria exist, management develops criteria and discloses them

What ISA 810 does not cover: Interim financial statements or condensed interim financial information (these fall under ISRE 2410 on reviews). ISA 810 specifically addresses annual summary financial statements derived from the full audited accounts.

Same Auditor Requirement

This is non-negotiable. If the entity's financial statements were audited by Firm A, only Firm A can report on the summary financial statements. If Firm B is asked to provide a report on the summary, Firm B must decline. The reason is that the report on the summary depends on the audit already performed — a different auditor would need to perform separate procedures that go beyond ISA 810's scope.

Engagement Acceptance

The auditor must evaluate two conditions before accepting:

Condition 1 — The Auditor Has Been Engaged to Audit the Complete Financial Statements

ISA 810 cannot be performed in isolation. The prerequisite is a completed or substantially completed audit of the complete financial statements from which the summary is derived.

Condition 2 — The Applied Criteria Are Acceptable

The auditor evaluates whether the criteria for preparing the summary financial statements are acceptable in the circumstances. Acceptable criteria will result in summary financial statements that:

Adequately disclose their summarised nature and identify the audited financial statements
Clearly describe which applied criteria were used (by reference to law, regulation, or a note)
Do not contain information that is inconsistent with the audited financial statements
Provide adequate disclosure at the level of aggregation or disaggregation necessary to avoid misleading users

When established criteria do not exist, the auditor evaluates management-developed criteria. These must be disclosed in the summary financial statements (typically in a note describing the basis of preparation).

Unacceptable criteria example: Summary financial statements that include only selected highlights (such as only revenue and profit) without providing a balanced structured representation would not meet acceptable criteria. The summary must provide a structured representation consistent with the complete financial statements, even though it contains less detail.

Procedures

ISA 810 procedures are not an audit of the summary financial statements. The auditor performs the following:

Read the auditor's report on the complete financial statements to ensure the opinion is fresh in mind
Compare the summary financial statements with the audited financial statements to assess whether the summary is consistent or a fair summary
Evaluate the applied criteria — Has management applied the criteria consistently? Are aggregation levels appropriate?
Consider the adequacy of disclosures — Do the notes in the summary adequately describe the basis of preparation and the summarised nature?
Evaluate the overall presentation — Could a user be misled by the summary's presentation or omissions?

These procedures are typically performed during or immediately after the completion of the audit of the complete financial statements.

Subsequent Events

When the auditor's report on the summary financial statements is dated later than the report on the audited financial statements, the summary report must include a statement that the financial statements and the summary financial statements do not reflect events occurring after the date of the auditor's report on the complete statements. The auditor does not perform additional subsequent events procedures for the summary engagement.

Forming the Opinion

Unmodified Opinion

When the auditor concludes the summary financial statements are consistent with (or are a fair summary of) the audited financial statements, the opinion uses one of two formulations:

Formulation 1: "The summary financial statements are consistent, in all material respects, with the audited financial statements, in accordance with [the applied criteria]."

Formulation 2: "The summary financial statements are a fair summary of the audited financial statements, in accordance with [the applied criteria]."

The choice between formulations may be determined by law or regulation, or by the terms of the engagement. Both express the same level of assurance.

Modified Opinions on the Complete Financial Statements

The opinion on the complete financial statements directly affects the summary financial statements report:

Complete FS Opinion	Impact on Summary Report
Unmodified	Auditor may express unmodified opinion on summary if consistent
Qualified	Auditor may express unmodified opinion on summary BUT must describe the qualification, state the summary is misstated to equivalent extent, and cross-reference
Adverse	Auditor shall not express an opinion on the summary — must state that it is inappropriate to express an opinion because the audited statements received an adverse opinion
Disclaimer	Auditor shall not express an opinion on the summary — must state that it is inappropriate because a disclaimer was issued on the complete statements

Qualified Opinion Nuance

When the auditor has expressed a qualified opinion on the complete financial statements, the summary report can still be issued — but it must be transparent. The report describes the qualification, indicates that the summary is misstated to the equivalent extent, and includes a reference to the auditor's report on the complete financial statements. Users of the summary should not receive a "cleaner" picture than users of the full accounts.

Adverse Opinion on the Summary

When the summary financial statements are not consistent with the audited financial statements and management does not agree to make the necessary changes, the auditor must express an adverse opinion. Note that ISA 810 does not provide for a qualified opinion on the summary — the opinion is either unmodified or adverse. The reason is that the comparison against the audited statements is binary: the summary is either consistent or it is not.

Report Structure

The auditor's report on summary financial statements includes:

Element	Content
Title	Clearly identifies it as a report on summary financial statements
Addressee	As appropriate for the intended recipients
Identification	Identifies the audited financial statements from which the summary derives
Complete FS opinion	States the type of opinion expressed on the complete financial statements
Complete FS report date	Includes the date of the report on the complete financial statements
Opinion	States the conclusion on the summary financial statements
Statement	The summary is not a substitute for reading the audited financial statements
Going concern	If the complete FS report included a Material Uncertainty Related to Going Concern section, the summary report describes this
KAM	If the complete FS report included KAM, the summary report describes this (if law/regulation requires or auditor decides)
Signature, date, address	Standard elements

Availability of the Complete Financial Statements

The auditor evaluates whether the complete financial statements are available to users of the summary financial statements without undue difficulty. If not, the auditor considers whether the summary adequately describes this limitation.

Documents Containing Summary Financial Statements

When summary financial statements are included in a document that also contains other information (such as a summary annual report), the auditor considers whether the form and content of the report are appropriate and reads the other information in the document for consistency with the summary financial statements and the auditor's knowledge.

Common Scenarios

Cooperative annual general meeting. A large cooperative distributes a summary annual report to its thousands of members ahead of the AGM. The complete audited financial statements are available on request or online. The auditor reports on the summary financial statements included in the summary annual report.

Employee communication. An entity prepares a simplified version of its accounts for distribution to employees as part of annual reporting to works councils or employee representative bodies. Where an auditor's report is requested, ISA 810 applies.

Regulatory publication. A regulator requires entities to publish summary financial information in a specific format. When an auditor's report on this published summary is required, ISA 810 governs the engagement.

Parent company summary for subsidiary investors. A parent publishes summary consolidated financial statements for investors who do not have access to the full accounts of operating subsidiaries.

Charity or association member communication. A charity or vereniging distributes a simplified financial summary to donors or members alongside a narrative annual review.

European Jurisdiction Implementations

Netherlands

Dutch practice encounters ISA 810 engagements primarily in the cooperative sector (coöperaties), where organisations like Rabobank historically distributed summary financial information to members alongside full cooperative annual reports. NBA Standard 810 aligns with the international standard. Additionally, Dutch stichtingen and verenigingen may publish simplified financial summaries for stakeholders, particularly when the full jaarrekening is complex. The Burgerlijk Wetboek does not specifically address summary financial statements, so the applied criteria are typically developed by management or follow sector-specific guidance.

Germany

ISA 810-equivalent engagements in Germany arise under IDW PS 810 primarily for Genossenschaften (cooperatives), which may distribute summary financial information to their large memberships. Large German mutuals and cooperatives in the insurance and banking sectors may prepare summary accounts for member communications. The Prüfungsstandard provides guidance adapted to German reporting conventions. Additionally, some German entities publish verkürzte Abschlüsse (condensed accounts) in the Bundesanzeiger (Federal Gazette) — when these are presented as derived from audited financial statements and accompanied by an auditor's report, ISA 810 principles apply.

United Kingdom

ISA (UK) 810 aligns closely with the international standard. The Companies Act 2006 (sections 426–429) previously regulated summary financial statements for public companies, though this route has become less common as digital distribution of complete financial statements has become standard. However, ISA (UK) 810 engagements still arise for building societies (which distribute summary financial information to members), friendly societies, and cooperatives. The FRC has noted that the decline in printed summary financial statements may be offset by increasing digital summary communications. Charities preparing a summary of the Trustees' Annual Report and Accounts for donor communications may also engage auditors under ISA (UK) 810 principles.

France

French practice under NEP 9510 addresses summary financial statements (comptes résumés). These engagements arise for mutuelles (mutual organisations), coopératives, and associations that distribute simplified financial information to their members or sociétaires. The commissaire aux comptes must ensure that the comptes résumés are consistent with the comptes annuels certifiés and that the condensation does not create a misleading impression. French cooperative banks and mutual insurers are frequent users of summary financial reporting for their large policyholder or member bases. The AMF (Autorité des Marchés Financiers) may also have specific requirements for listed entities publishing summary financial information in documents de référence or rapports annuels résumés.

Relationship with Other Standards

ISA 700 — The summary report references the opinion expressed under ISA 700 on the complete financial statements
ISA 705 — A modified opinion on the complete financial statements directly impacts the summary report (qualified triggers disclosure; adverse/disclaimer prevents opinion)
ISA 570 — Material uncertainty related to going concern must be carried through to the summary report
ISA 701 — KAM from the complete audit may need to be referenced or described in the summary report
ISA 720 — Other information accompanying the summary financial statements requires reading and consideration
ISRE 2410 — Reviews of interim financial information are distinct from ISA 810 engagements and should not be confused

Frequently Asked Questions

Can a different auditor report on summary financial statements?

No. ISA 810 requires that the same auditor who audited the complete financial statements reports on the summary financial statements. A different auditor must decline such an engagement because the report on the summary depends on the audit already performed — a different auditor would need to perform separate procedures that go beyond ISA 810's scope.

What type of opinion can be expressed on summary financial statements?

The opinion on summary financial statements is either unmodified or adverse. ISA 810 does not provide for a qualified opinion on the summary. The binary structure reflects the binary nature of the question: is the summary consistent with the complete accounts, or is it not?

What happens if the complete financial statements received a qualified opinion?

When the auditor expressed a qualified opinion on the complete financial statements, the summary report can still be issued with an unmodified opinion — but it must describe the qualification, indicate that the summary is misstated to the equivalent extent, and include a reference to the auditor's report on the complete financial statements.

Does ISA 810 apply to interim condensed financial information?

No. ISA 810 specifically addresses annual summary financial statements derived from the full audited accounts. Interim financial statements or condensed interim financial information fall under ISRE 2410 on reviews, which is a separate engagement standard.