Zero-balance accounts: sweep subsidiary cash to a header account every day

A zero-balance account structure physically sweeps participating account balances to a central header account, normally every day. Unlike notional pooling, legal ownership of the swept cash changes and the operating company replaces its external bank deposit with an intercompany balance against the pool header.

Daily sweeps concentrate cash physically

HMRC's September 2026 cash-pooling guidance describes zero balancing, also called cash concentration or physical cash sweeping, as moving excess cash from participant accounts to a header account. A target-balancing variation leaves a predetermined amount in the local account.

The structure gives treasury direct control of group liquidity instead of only an interest calculation across separate balances.

The sweep creates intercompany positions

When a subsidiary's cash moves to the header, the subsidiary no longer holds the external deposit. Economically it can become a lender to the pool header, while an entity funded from the header becomes an intercompany borrower.

Record those balances automatically if possible. Treating the sweep as a simple transfer with no counterparty ledger leaves statutory accounts wrong.

Participants need enough local cash for payment cut-offs

An account swept to zero overnight can still need money the next morning for payroll, tax or supplier payments. The bank or treasury system must fund the account before cut-offs or allow payments to draw from the pool structure.

Set target balances for accounts with unpredictable same-day debits. The highest interest efficiency is not useful if ordinary payments bounce.

Internal deposit and borrowing rates matter

The pool header can earn a spread between what it pays cash-rich companies and charges cash-short companies, but transfer-pricing rules require an arm's-length analysis where applicable.

HMRC guidance also distinguishes genuinely short-term balances from structural deposits or borrowing that remain in the pool for long periods. Long-term balances can need different pricing.

Protect the header account as a concentration point

The header can contain most of the group's liquid cash, making it a high-value fraud target. Use stronger payment limits, limited administrators and dual approval for movements out of the pool.

Keep external bank diversification in mind. Physical concentration can improve visibility while increasing dependency on one banking group.

Reconcile the sweep and intercompany ledger every day or month

Participant bank statements should show the physical sweep, while the intercompany ledger records the matching receivable or payable. The header company needs the opposite entries.

Differences can arise from bank cut-offs, value dates or failed sweeps. Resolve them promptly rather than allowing a permanent intercompany suspense balance to build.

Worked example: Subsidiary A ends the day with £800,000 and Subsidiary B ends £250,000 overdrawn. Treasury sweeps A's £800,000 to the header and funds B's deficit from the header. The group reduces external borrowing, while A now has an intercompany receivable and B an intercompany payable.

Keep local tax and regulatory needs in the target-balance design. Some subsidiaries cannot be swept to zero because they need legally or operationally ring-fenced liquidity.

Review automatic sweeps after weekends and holidays. Value dates can create unexpected overdrafts if the header and participant countries follow different banking calendars.

Set a daily sweep timetable around local payment cut-offs. A subsidiary can receive customer cash after the evening sweep or need supplier funds before the morning reverse sweep. The treasury system should define when local balances are measured and how intraday deficits are funded so automatic concentration does not create accidental overdrafts.

Worked example: Subsidiary A finishes with £1.2 million, Subsidiary B with £400,000 and Subsidiary C at minus £300,000. At the sweep, A and B send £1.6 million to the header and the header funds C's £300,000 deficit. The pool header ends with a £1.3 million net external balance while three matching intercompany positions are created internally.

Use participant limits. A company should not be able to draw unlimited internal funding merely because the header account contains surplus from other subsidiaries. Treasury can set borrowing caps, approved purposes and escalation levels just as an external bank would.

Test the structure during bank outages. If the automatic sweep fails, local accounts can retain unexpected surpluses or deficits. Treasury needs a manual funding route and a reconciliation procedure for the next business day.

Set a formal participant-entry and exit process. A newly acquired subsidiary should join only after mandates, intercompany documentation and tax analysis are ready, while a company being sold should exit before its cash remains automatically swept to a former group header after completion.

Reconcile bank value dates, not just posting dates. Cross-border sweeps can appear one day apart between participant and header accounts, creating temporary intercompany differences that should be explained rather than forced to zero.