How to read the Budget documents: the Red Book and the OBR forecast

Updated 2026-10-13

Edited by Mistabilda, Editor

Every Budget comes with two core documents. The Treasury's Budget document, known as the Red Book, sets out the government's decisions and a table of what each one costs or raises. The Office for Budget Responsibility's Economic and fiscal outlook gives the independent forecast for the economy and public finances. Use the Red Book to find what was decided and the OBR to judge the forecast effect. The next Budget and OBR forecast are due on 28 October 2026.

The documents and who writes them

The Budget document (Red Book) , published by HM Treasury on GOV.UK. It explains the government's choices and lists every policy decision with its cost or yield. Budget 2025 was published on 26 November 2025 as a web, print and HTML document .

Supporting documents , including policy costings (the method behind each figure) and "Impact on households", the distributional analysis.

The OBR's Economic and fiscal outlook (EFO) , the independent forecast published on the same day. The OBR also certifies the Treasury's costings as reasonable central estimates. See our OBR source guide and what the OBR is .

A spring forecast usually comes with a shorter statement rather than a full Budget. The OBR published an EFO in March 2026 , and has said it will publish the next one "on 28 October alongside the Budget" ( OBR announcement ).

Sources: web, print and HTML document, policy costings, March 2026, OBR announcement

Step 1: find the policy decisions table

The single most useful page in the Red Book is the table of policy decisions, sometimes called the scorecard. In Budget 2025 it is in chapter 5, "Policy Decisions", headed "Budget 2025 policy decisions (£ million)", with a column for each year from 2025-26 to 2030-31. The document says it "shows the cost or yield of all government decisions accounted for at Budget 2025 which have a direct effect on Public Sector Net Borrowing".

Read the signs carefully. A positive number reduces borrowing (tax raised or spending cut); a negative number increases it. Each row is labelled Tax or Spend.

Worked example: the income tax threshold freeze

Suppose someone says "the Budget raises £12 billion a year by freezing tax thresholds". In the Budget 2025 decisions table we found:

Row 46, "Personal Tax: Maintain the personal income tax and equivalent national insurance thresholds at current levels for a further three years until April 2031": £0 in 2025-26 and 2026-27, then -£25m, +£3,365m, +£7,780m and +£12,435m in 2030-31 .

Row 47, the employer National Insurance threshold freeze: +£925m in 2030-31.

So the £12 billion figure matches one row in one year, 2030-31, the end of the forecast. It does not apply "a year" now: the measure raises nothing until 2028-29, because the thresholds were already frozen until April 2028. A fuller description would be "the extended freeze is costed at £12.4 billion in 2030-31 (HM Treasury, Budget 2025, table of policy decisions)". For the policy itself see fiscal drag and the personal allowance .

The bottom of the same table gives totals. For Budget 2025, total tax policy decisions were +£26,645m in 2030-31 and total spending decisions -£2,535m, so the package as a whole reduced borrowing in that year by £24,110m.

Step 2: use the OBR for the forecast picture

The Red Book reports the OBR's numbers, but the EFO has the detail and the caveats. The chapters most people need are the economy forecast, the fiscal outlook (receipts and spending), and performance against the fiscal rules. Look for:

Tax as a share of GDP. In March 2026 the OBR forecast National Accounts taxes rising "from 34.5 per cent of GDP in 2024-25 to a peak of 38.5 per cent of GDP by the end of the forecast period". See how to check a claim that taxes are going up .

Uncertainty. The same EFO notes that "the average absolute five-year forecast difference for receipts as a share of GDP is 0.9 percentage points". A forecast five years out is not a promise.

Changes since the last forecast. The EFO separates changes caused by policy from changes caused by the economy or data, which tells you whether a figure moved because of a decision.

The charts and tables files let you take a number straight from the source table.

Source: charts and tables

Step 3: check the language of a Budget claim

"By the end of the forecast" usually means the last year in the table, five years ahead.

"Cumulative" or "over the forecast" means several years added together. A £5 billion-a-year measure becomes £25 billion over five years.

Cash or real terms. Budget tables are in cash. See cash terms and real terms .

Borrowing or debt. Borrowing is the yearly gap; debt is the stock. See PSNB and PSND .

Forecast or outturn. Budget figures for future years are forecasts. Later outturn comes from the ONS public sector finances; see outturn .

For checking a promise made in a speech rather than in the documents, see how to check a spending pledge .

Step 4: check claims about who gains and loses

Claims that a Budget helps or hurts particular households should be checked against the Treasury's "Impact on households" document, which sits among the supporting documents. The Budget 2025 Red Book summarises it: "On average, all but the richest 10% of households will benefit as a percentage of income from overall policy decisions in 2028-29." Note the conditions in that sentence: an average across income groups, a percentage of income rather than pounds, decisions since Autumn Budget 2024, and one year, 2028-29. A claim about a particular family type, or about a different year, needs a different table or cannot be answered from this analysis.