GBTT Data Release · Fiscal
April delivers the message Westminster keeps trying not to hear. Borrowing of £24.3 billion is up 25% on last April and £3.4 billion above the OBR’s own forecast — in the first month of the fiscal year, when accruals typically flatter the picture. Debt interest of £10.3 billion in a single month is the highest April on record, with £2.9 billion of it pure RPI capital uplift on index-linked gilts. The UK now runs a permanent fiscal deficit irrespective of the cycle, and its sensitivity to inflation has made monetary and fiscal policy structurally inseparable. The bond market is patient, not blind.
April 2026 PSF · the headline numbers
The composition problem
The FYE March 2026 outturn looks reassuring at first glance: borrowing of £129.0 billion (4.2% of GDP), revised £3.0 billion lower than April’s initial estimate and £3.7 billion inside the OBR’s March forecast. That is the closing-cycle number. The opening-cycle number is what matters now, and it is moving the wrong way.
April’s composition tells the story. Central government current expenditure rose 6.5% year-on-year. Net social benefits added £2.7 billion on inflation- and earnings-linked uprating. Departmental spending on goods and services rose £1.7 billion. Debt interest rose £0.9 billion. Against all that, central government tax receipts grew just £1.8 billion. The current budget deficit — the cleanest measure of day-to-day fiscal health — widened to £17.4 billion, £3.4 billion higher than April 2025 and £2.6 billion above OBR. The arithmetic does not work.
The debt-interest line is the structural issue. £10.3 billion in a single month, £2.9 billion of which is index-linked capital uplift triggered by a 0.4% monthly move in RPI. Post-QE, the gilt stock’s duration profile and indexation share mean every inflation surprise feeds directly into the deficit and every basis point of yield matters. The Treasury is, in effect, short rates and short inflation simultaneously. This is not a fiscal posture compatible with sustained discretionary spending growth.
A £3.4 billion OBR overshoot in month one is small in absolute terms and large in signalling terms. Bond markets price trajectory, not single prints, and the trajectory now established is for spending growth comfortably ahead of receipts, with a debt-service line that is itself a function of the inflation the Bank is still trying to anchor. The Chancellor’s headroom against the fiscal rules was already minimal. April makes it more so.
Britain does not have a borrowing problem in isolation. It has a spending problem, a productivity problem, and an institutional refusal to acknowledge either. Welfare uprating, the triple lock, and unfunded departmental drift continue to crowd out the supply-side reform the economy actually needs. The April figures should be read accordingly.