PIP 2018 to 2025: the real-terms gap left by the September-CPI uprating lag

Every April, working-age benefits are uprated using the Consumer Prices Index from the previous September — a seven-month lag written into the Social Security Administration Act 1992. In quiet years the lag is invisible. During the 2021–23 inflation spike, when annual CPI moved from 3.1% to 10.1% and back to 6.7% in three steps, the lag produced a measurable real-terms gap for every indexed benefit, including Personal Independence Payment.

This piece reconstructs the headline PIP rates from April 2018 to April 2025, computes the cumulative CPI change over the same window using the April 12-month rate each year, and shows where a PIP claimant ended up in real terms. The gap is smaller than many assume — 1.49% over seven years — but it is real, and it is concentrated in two benefit years.

The headline numbers

Between April 2018 and April 2025, the enhanced rate of PIP Daily Living rose from £85.60/week to £110.40/week — a nominal increase of 28.97%. Over the same period, CPI rose 30.91%, using the ONS D7G7 12-month CPI rate measured at April of each year.

The real-terms change is −1.49%, or equivalently £1.66 a week / £86.32 a year below where pure CPI indexation would place the enhanced daily-living rate. Standard Daily Living (£73.90) is short by £1.10/week, Enhanced Mobility (£77.05) by £1.15/week, and Standard Mobility (£29.20) by £0.44/week.

Where the gap was created

The cumulative 1.5% shortfall is not evenly distributed. Five of the seven benefit years produced a surplus (i.e. PIP rose by more than contemporaneous April CPI) because the September-CPI figure for the uprating order overshot the following year's actual inflation. The deficit comes almost entirely from the April 2022 uprating:

• April 2022: PIP was uprated by 3.1% (September 2021 CPI). April 2022 CPI was 9.0%. In the gap between the uprate decision and the uprate date, the real value of PIP fell by 5.9 percentage points — a drop that no later uprating fully caught up.
• April 2023: PIP was uprated by 10.1% (September 2022 CPI). April 2023 CPI was 8.7%. Claimants gained 1.4 points back here — a genuine real-terms boost that partially offset 2022's loss.
• April 2024: 6.7% uprating vs 2.3% April CPI — a 4.4 point surplus.
• April 2025: 1.7% uprating vs 3.5% April CPI — another 1.8 point deficit.

Net of all seven uprate events, the enhanced daily-living rate is £1.66/week below where April-to-April CPI indexation would put it. The gap would be closed by one uprating year of above-CPI increase — which is approximately what the 2023 order delivered, at 10.1% against 8.7% contemporaneous CPI.

The data

The table below reconstructs each year's PIP enhanced daily-living rate alongside the CPI indexation counterfactual. The counterfactual starts from the actual April 2018 rate and compounds the ONS April 12-month CPI each year. “Cumulative nominal” and “cumulative CPI” both use £85.60 as the April 2018 baseline.

Scale of the effect

At April 2025 the DWP's caseload report showed approximately 3.7 million PIP claimants in England and Wales, with about 52% receiving the enhanced rate of daily living. At a £1.66/week shortfall on the enhanced rate and £1.10/week on the standard rate, the total monthly value of the CPI-indexation gap to PIP claimants is in the order of £12 million a month, or £150 million a year. For comparison, each PIP claimant is owed approximately £7 a month back against contemporaneous inflation — smaller than the DWP's own Personal Allowance uprating for a single claimant but large in aggregate.

Why this matters beyond the arithmetic

The mechanical argument for the September-CPI lag is straightforward: uprating orders must be laid before Parliament with enough time to take effect on the first day of the new financial year, and the September CPI release is the latest data available when that process begins. A move to a more contemporaneous measure would require a legislative change to the uprating architecture. The Social Security Advisory Committee has raised this question in past reports but no government has acted.

The CPI itself is also a debated measure for households with high essential-spend shares. Between April 2018 and April 2025, ONS CPI for food and non-alcoholic beverages rose by approximately 37% (series CPIH-consistent) — meaningfully more than headline CPI's 30.9% — and wholesale gas prices rose and then largely normalised, leaving the retail price cap substantially above its 2018 level. A PIP claimant who spends a higher-than-average share of their income on food and energy is likely to have experienced higher inflation than this analysis measures.

Methodology

This analysis uses the following data and assumptions:

• Actual PIP rates are from the DWP's “Benefit and pension rates” publications for each of the years 2018–19 through 2025–26. These are the statutory weekly rates that appear in the Social Security Benefits Up-rating Orders and apply from the first Monday on or after 6 April each year.
• Uprating percentages are the September CPI 12-month rates for the year preceding each uprating. For April 2018 this is September 2017 CPI (3.0%); for April 2025 it is September 2024 CPI (1.7%). These are the figures used in each year's Up-rating Order.
• April CPI 12-month rates are from the ONS D7G7 series, measured at April of each year. The counterfactual column compounds the April 2018 rate (£85.60) by each subsequent April's 12-month CPI, which represents the inflation actually experienced in the year ending at each uprate date.
• Rounding. Weekly rates are rounded to the nearest penny per DWP convention. Percentage changes are computed to two decimal places from unrounded pence values.
• Caveats. This analysis does not model transitional protections, reassessment-induced rate changes (PIP claimants can have their rate revised up or down at periodic review), passported-benefits value (free prescriptions, Blue Badge eligibility, motability), or any element of real-terms analysis beyond headline CPI. Nor does it consider the counterfactual cost of a contemporaneous-CPI uprating methodology to the Exchequer.

Related analysis

This finding is consistent with published research by the Joseph Rowntree Foundation on inflation lags in working-age benefits, and with analysis by the Resolution Foundation on the 2022–23 uprating shortfall. Where this piece differs is that it isolates PIP specifically — a benefit that has no income or capital taper and is paid regardless of employment status, so the uprating gap is the sole determinant of real-terms change.

If you want to check whether you might be entitled to PIP, our PIP points self-check walks you through the 2024-regulation activity / descriptor tables, and the broader How to apply for PIP guide covers the application and assessment process.

For the current weekly PIP figures and a full table of 2025-26 uprating across all major benefits, see our 2026 uprating tracker.