Notional cash pooling: offset group balances for interest without physically sweeping the cash

Notional cash pooling lets a banking group calculate interest on the net credit and debit positions of participating accounts while cash remains in each legal entity's own account. HMRC's September 2026 cash-pooling guidance distinguishes this from zero balancing, where funds physically move to a header account and ownership changes.

Cash stays in the participating entity accounts

HMRC describes notional pooling as an arrangement where the group nets different account balances for interest purposes without physically transferring the cash to a header account. The legal ownership of each bank balance therefore remains with the original company.

This can reduce the group's external overdraft interest while preserving local account ownership and transaction capability. The bank calculates a group benefit based on the combined positions.

The main economic benefit is interest netting

If one subsidiary has £4 million cash and another has a £3 million overdraft, notional pooling can allow the bank to price interest closer to the group's £1 million net credit position instead of charging full borrowing cost while paying lower deposit interest separately.

The exact bank pricing depends on currencies, country rules and the pooling agreement. Treasury should measure the actual saving after fees rather than assume all debit and credit interest disappears.

Legal ownership is different from economic netting

Because cash does not move, Subsidiary A's positive account remains its asset and Subsidiary B's overdraft remains its liability. Consolidated group reporting can show the economic benefit while entity accounts still record their own balances.

Do not post notional sweep entries merely because treasury views the pool on a net basis. Accounting should follow the actual legal and bank movements.

Banks can require cross-guarantees or set-off rights

The bank takes credit risk where one participant is overdrawn and another is in credit. Pool agreements can therefore require guarantees, cross-account set-off or other support between participating companies.

Directors should understand those commitments before joining. A cash-rich subsidiary can indirectly support another group company's bank debt even though its own cash never moved.

Cross-currency pools need careful pricing

HMRC's cash-pooling guidance notes that multiple currencies add complexity and that netting different currencies may not be appropriate unless the commercial bank arrangement actually permits it. Interest rates can differ substantially between sterling, euros and dollars.

Keep currency-level reporting. A group with net positive sterling and net negative dollars can still have a genuine dollar funding requirement despite a healthy total group cash figure.

Allocate the pool benefit on an arm's-length basis

HMRC expects the allocation of cash-pool benefits among depositors, borrowers and the pool header to follow transfer-pricing principles where applicable. Interest rates are a common way of sharing the benefit.

Review long-term structural balances separately. A subsidiary that leaves large cash permanently in a short-term pool may need a different arm's-length return from an entity whose balance genuinely fluctuates daily.

Worked example: Company A has £5 million credit, Company B is £2 million overdrawn and Company C is £1 million overdrawn. The bank can calculate pool economics on a £2 million net credit position while each company keeps its own account balance. No physical £3 million transfer to A or a treasury header is required.

Use a participant agreement that explains guarantees, interest allocation and termination. A company leaving the group may need to exit the pool before the legal sale date so its bank exposure is no longer tied to former affiliates.

Reconcile the bank's interest benefit to internal allocation monthly. The group's external saving should not disappear into one treasury entity without a supportable explanation of how participating companies are compensated.

Document how the bank calculates debit and credit interest. The contractual benefit can depend on whether balances are notionally offset by currency, by country or across the full pool and on whether the bank applies separate spreads to debit and credit positions. Treasury should be able to reproduce the monthly pool benefit from participant balances.

Worked example: four sterling companies hold credits of £7 million and overdrafts of £5.5 million. Without pooling, the group can pay overdraft interest on £5.5 million while earning lower deposit interest on £7 million. Notional pooling can price the bank relationship closer to the £1.5 million net credit position, subject to the bank's spread and legal structure.

Review participant solvency and guarantee exposure annually. A cash rich subsidiary can remain legally separate while its guarantee supports an overdrawn affiliate. Directors should understand that joining the pool can create contingent risk even when no physical cash transfer appears on their bank statement.

Review the pool when interest rates diverge sharply between currencies or entities. A structure that saved meaningful interest when rates were similar can become less efficient after market changes, particularly where bank spreads and guarantee fees rise.