Parliamentary Accountability Cycle

What are the key stages of the UK parliamentary accountability process?

The UK parliamentary accountability process operates in three broad stages.

• NAO value for money programme The NAO's work-in-progress notice provides the first public signal that a value for money study is underway. The NAO gathers and assesses evidence and lays its report in Parliament. These reports may be a full value for money report containing findings, conclusions and recommendations, a set of findings derived from a facts-based investigation, an insights report or briefing.
• Public Accounts Committee inquiries The PAC stage has three components: the inquiry, oral hearings and report. The PAC routinely uses an NAO report as the primary basis for its inquiries and convenes oral evidence sessions with senior officials from the audited body and relevant parties, following which it publishes a report and recommendations.
• Government response The government's formal response to the PAC is published as a Treasury Minute. This addresses the recommendations of the PAC. The NAO tracks its recommendations separately and reports on the progress of implementation through its annual report and accounts.

How long does the UK parliamentary accountability cycle take?

The process from the NAO first publishing a work-in-progress notice to the government's formal response in a Treasury Minute spans, on average, 304 days (median), around ten months. This breaks into roughly 84 days from the work-in-progress notice to the published NAO report, and a further 192 days from publication to the Treasury Minute response.

Figure 1: Accountability cycle — median milestone intervals

The chart below shows the distribution of end-to-end timescales across 83 completed accountability cycles by combining data from the NAO, PAC and Treasury. Caution should be taken due to inconsistencies and revisions. The six stages are: Step 1: NAO WIP notice published. Step 2: NAO report published. Step 3: PAC inquiry opened. Step 4: PAC oral evidence session and other committee business. Step 5: PAC report published. Step 6: Government response to the PAC contained in correspondence and the Treasury Minute. Note that the date of Step 3 routinely precedes Step 2.

Figure 2: Accountability cycle — median intervals anchored to PAC inquiry opening

Figure 3: Distribution of accountability cycle end-to-end timescales

WIP notice to Treasury Minute · 83 completed cycles, July 2021 – January 2026

This analysis covers cases where all key dates are available — currently 83 completed cycles from 9 July 2021 to 9 January 2026. The count will grow as the database expands. WIP announcement dates have been derived in part from historical records via the Internet Wayback Machine. The data is unaudited and may be limited in accuracy.

Source: SDWH Limited analysis. Last updated 30 June 2026.

How likely is it that an NAO report will support a PAC inquiry?

Nine in ten NAO value for money reports support a subsequent PAC oral evidence session and published report. As of 30 June 2026, 118 of the 137 NAO reports published since January 2024 (86%) have supported a PAC oral evidence session, with 19 published reports yet to be taken up by the committee — the majority of which were published in the first half of 2026 and remain within the normal pre-inquiry window. Conversely, 96% of PAC oral evidence sessions in the same period (109 of 113) drew directly on a published NAO report as their primary basis. The committee's scrutiny programme is therefore substantially shaped by the NAO's choice of topics and the pace of its publication programme.

Source: SDWH Limited analysis, January 2024 – June 2026. Last updated 30 June 2026.

Figure 6 tracks the cumulative connection ratios since January 2024. The proportion of PAC oral evidence sessions referencing a published NAO report has remained above 96% throughout the period, reflecting the structural dependence of the committee's programme on NAO output. The proportion of NAO reports not yet supporting any PAC inquiry fell steadily through 2024 and into mid-2025 as older reports were taken up by the committee, but has risen since March 2026 as the most recently published reports are still within the typical pre-inquiry window before the PAC formally opens an inquiry.

Figure 6: Cumulative NAO-PAC connection ratios over time

Running percentages since January 2024 — PAC hearings referencing NAO reports, and NAO reports not yet supporting a PAC inquiry

Source: SDWH Limited analysis. Last updated 30 June 2026.

The NAO produces three broad report types. Value for money studies typically contain findings, a conclusion and recommendations. Investigations typically contain factual findings. Insight reports include lessons-learned, good practice guides and occasional briefings. The PAC takes evidence from a variety of NAO report types and also draws on the NAO's financial audit work as well as running standalone inquiries that are not related to NAO outputs.

Source: SDWH Limited analysis, January 2024 – June 2026. Last updated 30 June 2026.

Monthly volumes: PAC oral evidence sittings and NAO publications

Between January 2024 and June 2026, the NAO published 137 value for money, investigation and insight reports, averaging 4.6 per month across the 30-month period. PAC oral evidence sessions linked to NAO reports totalled 113 over the same period, averaging 3.8 per month. The highest single-month volumes of NAO publications were March 2024 and March 2026 (10 reports each), both approaching financial year-end. There were no NAO publications in June or August 2024 and no PAC sittings from June to October 2024, owing to the UK General Election in July 2024. The NAO lays reports in Parliament, which means that recesses and dissolution periods result in gaps in the publication record. The NAO reports on total publication volumes in its annual report and accounts covering the financial year ending 31 March.

Figure 9: Monthly volumes — PAC oral evidence sittings and NAO publications

Jan 2024 – Jun 2026 · grouped by month

Source: SDWH Limited analysis. Last updated 30 June 2026.

How does the NAO assess and report the financial impact of its work?

In 2024–25 the NAO's confirmed financial impact was £5,273m: £53 for every £1 of net expenditure, compared with approximately £17 for every £1 in 2023–24. The NAO reports on the financial impact of its value for money programme in its annual report. This methodology applies five principles: causation (a causal link between the NAO's work and the benefit), realisation (the impact has occurred within or before the reporting year), valuation (reliable data support the claim), attribution (the proportion claimed reflects the degree of the NAO's contribution) and validation. In July 2024 the NAO Board changed its financial impact methodology to remove the need for audited bodies to formally agree on causality and attribution of financial impacts, and established a formal role for an Impact Panel to approve financial impacts, with a non-executive director member of the panel.

Source: NAO Annual Report and Accounts 2024–25.

What proportion of NAO reports have been linked to a quantified impact?

The NAO publishes around 60–70 value for money and insights reports each year. Over the six-year period 2020–21 to 2025–26 a total of 79 individual impact claims have been published. The NAO applies a five-principle methodology to the subset of reports for which an impact case is constructed. Whether reports not mapped to any financial impact generated benefits that were not captured, or generated no measurable benefit, cannot be determined from the available information.

Figure 10: NAO impact claims by recognition year — count and average value per claim

2020–21 to 2025–26 · 79 individual impact claims

Source: NAO Annual Reports 2021–22 to 2025–26.

How is NAO financial impact distributed across topic areas?

Over the six-year period 2020–21 to 2025–26, three themes — tax & compliance, infrastructure & capital, and commercial & procurement — are closely clustered, each at approximately £3bn of cumulative recognised impact, together accounting for around three-quarters of the total. NHS & health, at £361m, reflects a consistent but more modest contribution. The theme categorisation spans both recurring stream impacts and one-off items assigned by subject matter.

Figure 11: NAO financial impact by theme — six-year cumulative, 2020–21 to 2025–26

Source: SDWH Limited analysis of NAO Annual Reports 2021–22 to 2025–26.

How recent are the reports that generate the NAO's current financial impact claims?

The chart below uses a Marimekko format in which each column's width is proportional to that recognition year's total impact: 2024–25 was by far the largest at £5.3bn and occupies the most horizontal space. Within each column, segments show the financial year of publication of the underlying NAO report — from pre-2014-15 (darkest) at the bottom, through to the most recent 2025-26 reports at the top. In 2025–26, reports published since 2020 account for the majority of recognised impact for the first time.

Figure 12: Origin-cohort composition of financial impacts by recognition year

Source: SDWH Limited analysis of NAO Annual Reports 2021–22 to 2025–26. Column width proportional to total recognised impact that year. Cohorts stacked oldest (bottom) to most recent (top).

Which individual impact claims have been the largest?

The largest impact claim reported by the NAO in the last 6 years related to the £1.4bn 2024-25 impact claim for the report UK Guarantees Scheme for Infrastructure, published in 2015. This report generated 12% of the £11.8bn total over 6 years. The 10 largest impact claims combined delivered £7.0bn (59% of total).

Figure 13: Top 10 NAO impact claims by value, 2020–21 to 2025–26

Source: SDWH Limited analysis of NAO Annual Reports 2021–22 to 2025–26. Bars coloured by theme consistent with Figure 11. BADR figures reflect a disputed classification and appear twice as separate recognition-year claims.

What happens to NAO recommendations after the report is published?

The NAO publishes a recommendations tracker containing 1,191 distinct top-level recommendations across 296 reports over seven years. These concentrate on major projects, procurement, fraud and error. The NAO reported a 93% acceptance rate, exceeding its 90% target. 74% of mature recommendations have been implemented and 5–6% exit as "no longer relevant." 4% of recommendations include an explicit deadline and only 2% include a quantified target.

Source: NAO, Recommendations Tracker, 2024–25.

What does the NAO's value for money programme cost, and what is the cost per report?

In 2025–26, the combined cost of the NAO's value for money and wider assurance work was approximately £28.9m (+4.1% year on year), and it published 67 VFM and insights reports (75 in 2024-25). This implies an average cost of approximately £431,567 per published report (direct and indirect costs). This represented a +17% increase in cost per report since 2024-25 due mainly to the reduction in the number of Insights reports from 15 to 6. The NAO's gross operational cost in 2025–26 was £147m. Value for money and insights work therefore represents approximately 20% of the NAO's gross expenditure.

Source: NAO Annual Report and Accounts 2025–26.

Select committees and broader parliamentary scrutiny

Parliamentary select committees beyond the Public Accounts Committee — covering business, treasury, defence, home affairs and cross-cutting themes including outsourcing, major contracts and government guarantees — regularly examine questions that overlap with what the NAO and PAC cover. SDWH provides analytical briefing to help committees and their research staff understand the evidence base, identify the right questions and assess the claims made by government witnesses.

The structure of parliamentary accountability — independent audit leading to committee scrutiny and a formal government response — is common to many systems beyond the UK. SDWH provides comparative analysis and briefing for audit and accountability institutions in other countries, drawing on the analytical framework developed from the UK's experience and the publicly available evidence on how these systems perform in practice.

Primary data sources

All data on this page is compiled from publicly available information published under the Open Government Licence by the following bodies. SDWH Limited does not reproduce the underlying documents; it aggregates, structures and analyses the data independently.

• HM Treasury — Treasury Minutes The government's formal written responses to PAC reports, addressed to the committee and published as Command Papers. www.gov.uk/government/collections/treasury-minutes
• UK Parliament — Public Accounts Committee Publications, oral evidence transcripts, inquiry reports and the committee's forward work programme. committees.parliament.uk/committee/127/public-accounts-committee
• National Audit Office — Reports Value for money studies, investigations and insights reports laid in Parliament, together with the NAO's work-in-progress list and annual report. www.nao.org.uk/reports