An approved budget is a plan; execution is what actually happens to the money. The two diverge — often dramatically — and the gap is where much of PFM's real action is. This module covers budget execution: the controls that keep spending within authorisation, the arrears that accumulate when they fail, and the cash management that determines whether the government can pay its bills.
Budget credibility — the execution gap
Budget credibility is the degree to which actual spending matches the approved budget. Low credibility — large deviations between what was appropriated and what was spent — undermines the whole point of budgeting: if the budget bears little relation to reality, the legislature's authorisation is meaningless, planning is impossible, and the document is theatre. Typical patterns: development/capital budgets are under-executed (ambitious projects that don't get spent, often because of weak project readiness or mid-year cash shortages), while recurrent spending over-executes; and frequent supplementary budgets re-authorise a reality that has already departed from the plan. PEFA scores budget credibility precisely because it is so fundamental.
Commitment controls and arrears
How arrears (pending bills) build up
The critical execution control is the commitment control — the check that stops a ministry from ordering goods or services it has no budget or cash to pay for. The spending chain runs: commitment (placing an order) → verification (goods received) → payment. If a government controls only at the payment stage but lets ministries commit freely, it accumulates commitments it cannot pay — arrears (in Kenya, 'pending bills'). Arrears are insidious: they are a form of hidden borrowing (the government is financing itself by not paying suppliers), they don't show up in the headline deficit, they bankrupt suppliers and raise future prices (vendors price in the risk of late payment), and they accumulate into a large overhang that eventually demands a costly clearance. Controlling commitment — not just payment — is the cure, and its absence is one of the most common PFM failures.
The Treasury Single Account
The TSA: one government, one cash position
Governments historically held thousands of separate bank accounts — every ministry, project, and fund with its own balances scattered across commercial banks. The result: the government borrows expensively while idle cash sits unused in hundreds of accounts, and no one knows the true consolidated cash position. The Treasury Single Account (TSA) consolidates all government cash into a single account (or a unified structure) at the central bank, so the government sees and manages its whole cash position, eliminates idle balances, reduces borrowing costs, and gains control. The TSA is one of the highest-return PFM reforms — it is largely a plumbing change with a large fiscal payoff — and a centrepiece of reform across the region, including Kenya.
Cash management
With a TSA in place, the treasury can actively manage cash — forecasting the timing of revenue inflows and spending outflows, and smoothing the mismatch (revenue arrives lumpily; spending is continuous) through short-term instruments rather than crisis borrowing. Good cash management is what lets a government release funds to ministries predictably so they can execute their budgets; poor cash management forces erratic, unpredictable releases (cash rationing), which destroys ministries' ability to plan and is itself a major cause of under-execution and arrears. Cash forecasting links execution back to the realistic-revenue-forecasting theme of the cycle module.
IFMIS and the capability trap
Modern execution runs on an Integrated Financial Management Information System (IFMIS) — software that records commitments, verifies receipts, processes payments, and enforces controls in real time against the chart of accounts. A well-functioning IFMIS can hard-wire commitment control (the system simply won't let a ministry commit beyond its budget). But IFMIS implementations are notorious for the capability trap of the Governance course: the system is installed (the form) but the controls are bypassed, the data is incomplete, manual workarounds proliferate, and the discipline the system was meant to enforce never materialises (the function). Kenya's IFMIS experience includes both genuine gains and well-documented circumvention. The lesson is the recurring one: the technology enforces control only if the institution actually uses it as intended.
Exercise
A county government has accumulated a huge stock of unpaid bills to suppliers ('pending bills'), even though its budgets were approved and apparently balanced each year. Suppliers are going bankrupt and now charge the county a premium. (1) Explain how pending bills can accumulate even with approved, balanced budgets — identify the control failure. (2) Explain why these arrears are a form of hidden borrowing and why they don't show in the headline deficit. (3) Explain how commitment controls and an IFMIS could prevent recurrence, and why installing the IFMIS might not be enough. (4) The county also suffers erratic cash releases that leave development projects half-funded — connect this to cash management and the TSA.