AUD, Auditing and Attestation

Sources for Procedures to Obtain Evidence

Last reviewed 2026-09-14

The standards and authorities behind PocketCPA's AUD lessons on Procedures to Obtain Evidence. The topic rests on AU-C 500.

About this topic

Audit evidence does not arrive on its own. The auditor goes and gets it, using a defined set of procedures, and this topic covers what each of those procedures can and cannot prove.

The mix responds to assessed risk. Understanding what each procedure can and cannot prove is what lets an auditor design a response that actually addresses the assertion at risk.

Key points

• Substantive procedures are required for every relevant assertion of every significant account, regardless of control reliance.
• Tests of controls provide evidence about operating effectiveness and are required when the auditor plans to rely on controls.
• The five assertion categories for account balances: existence, completeness, valuation, rights and obligations, and presentation.
• Confirmation is a direct external response and is strong evidence for existence and rights assertions.

What the lessons cover

1. The categories of procedures
2. The seven techniques
3. Confirmations and analytics (AU-C 505, 520)
4. Sufficiency, appropriateness, and the reliability of evidence
5. Selecting items for testing
6. Timing: interim evidence and covering the remaining period
7. Specific items requiring special consideration (AU-C 501)
8. Opening balances in an initial audit (AU-C 510)

Authoritative references

Where these requirements sit. PCAOB paragraph numbers were quote-checked against the live standards.

• AU-C 500.
  • .05 sufficiency as quantity and appropriateness as quality comprising relevance and reliability.
  • .09 information produced by the entity, evaluated for accuracy and completeness and for sufficient precision and detail.
  • .A31 the reliability generalizations (independent external sources, obtained directly, documentary and original).
  • At section level it carries the seven techniques and their limits, the recalculation against reperformance line, the insufficiency of inquiry alone, and information prepared using the work of a management's specialist, distinct from AU-C 620 for an auditor's specialist, with neither referenced in an unmodified report.
• AU-C 501.
  • .07 procedures over changes between a count date other than period end and period end.
  • .10 confirmation of quantities and condition for third-party inventory plus additional procedures when significant.
  • .16 the letter of audit inquiry to external counsel as the primary means of corroborating litigation, claims and assessments, with refusal of permission a scope limitation warranting a qualified opinion or disclaimer.
  • At section level it carries attendance at the physical count (instructions and controls, observation, inspection, test counts, plus procedures over the final inventory records) and segment information.
• AU-C 505.
  • .07 control over the confirmation process.
  • .08 and .09 the ordered response to management's refusal, reaching those charged with governance under AU-C 260 and the opinion only at .09.
  • .12 alternative procedures for each nonresponse.
  • .14 the duty to investigate exceptions.
  • .15 the four conditions for negative confirmations as the sole substantive procedure.
• AU-C 510 at section level carries opening balances in an initial audit.
• AU-C 520.
  • .05 data reliability, precision, and the acceptable difference.
  • .07 inquiry plus appropriate corroborating evidence.
  • At section level, the mandatory overall review near the end of the audit, separate from the planning analytics under AU-C 315.
• AU-C 330 at section level carries tests of controls for reliance and the interim-date requirement.
• AS 1105.
  • .04 through .10A sufficiency, appropriateness, the relevance factors, the reliability generalizations, information produced by the company, and externally sourced information provided in electronic form.
  • .11 the five assertion categories.
  • .13 and .14 the three procedure categories and the purpose rule.
  • .15 through .21 the techniques.
  • .22 through .28 selecting items, with .24 on 100 percent examination and .27 barring projection of specific-item results.
  • .29 resolving inconsistent evidence.
  • Appendix A paragraphs .A3, .A4, .A6 and .A8 carry the company's specialist.
• AS 2301.
  • .11 tests of details for significant risks.
  • .16 and .17 effectiveness over the entire period of reliance and mandatory tests of controls where substantive procedures alone cannot suffice.
  • .36 substantive procedures regardless of control risk.
  • .24 and .39 the ranking and the insufficiency of inquiry.
  • .47 and .A2 the dual-purpose test.
  • .50 the items not selected.
  • .29, .30, .43, .45 and .46 the timing rules for interim control and substantive testing.
• AS 2305.
  • .09 and .10 insufficiency alone for a significant risk and unsuitability for detecting fraud.
  • .16 testing controls over the data or otherwise supporting completeness and accuracy.
  • .17 and .19 precision and disaggregation.
  • .21 corroborating responses and acting where none is available.
  • .22 documentation where an analytic is the principal substantive test.
• AS 2310.
  • .08 blank forms.
  • .12 and .13 negative requests alone as never sufficient and their permitted combination.
  • .14 through .16 control over the process.
  • .20 exceptions evaluated for misstatement and for control deficiency.
  • .21 through .23 follow-up, misdirected responses, and alternative procedures.
  • .24 and .25 the affirmative requirement for cash and receivables and the receivables-only escape.
  • .28 the audit committee communication.
  • .C2 examples of alternative procedures.
• AS 2505.
  • .08 the letter as primary means, inside counsel no substitute for what outside counsel withholds.
  • .12 permitted limitations that are not scope limitations.
  • .13 a refusal to furnish as a scope limitation precluding an unqualified opinion.
  • .14 inherent uncertainty as an uncertainty question.
• AS 2510.
  • .01 observation as a generally accepted procedure with the burden of justifying an opinion issued without it.
  • .10 observation during or after the period with reliable perpetual records.
  • .12 tests of the records alone as never sufficient.
  • .14 the four procedures for public-warehouse inventory including confirming pledged receipts with lenders.
• AS 2610.
  • .03 no acceptance until the communications are evaluated.
  • .06 the successor's initiative.
  • .08 client permission and the effect of a refusal.
  • .09 the matters to inquire about.
  • .10 the predecessor's duty to respond fully or state that the response is limited.
  • .11 workpaper access as a matter of judgment.
  • .13 sole responsibility with no reference to the predecessor's work in the report.
  • .15, .18 and .20 the reaudit rules.

How PocketCPA uses these sources

Every lesson is written in original words and cites the paragraph each rule comes from. No standard's text is reproduced. How lessons and questions are written and checked is set out in our methodology.

See also

• Sources for every AUD topic
• Free AUD sample questions
• The CPA exam glossary