What it means
Most businesses keep a cushion in the current account so that payments never bounce. That cushion often earns nothing at all, and across a year the forgone interest on a six figure balance is real money.
A sweep instruction fixes this mechanically. The bank sets a target balance, moves anything above it into a money market fund, deposit account or offset facility overnight, and moves it back the next morning or whenever a payment demands it.
There are two main varieties. An investment sweep parks surplus cash somewhere it earns interest, while a debt sweep uses the same balance to pay down a revolving credit facility, which saves the borrowing rate rather than earning the deposit rate.
For groups with several entities, cash pooling extends the same idea across accounts. Balances from many subsidiaries are notionally or physically combined so that one company's surplus offsets another's overdraft, which often saves more than any interest rate negotiation.
The trade offs are worth knowing. Swept funds may not carry the same deposit protection as a bank balance, transfers can carry fees, and money market funds carry a small amount of investment risk, so the arrangement should be sized against the interest actually gained.
In practice
Real-world examples.
Example
A veterinary practice group with $800,000 of average surplus sets a sweep to a money market fund at 4%. The arrangement earns roughly $32,000 a year with no change to how the practice managers handle payments.
Example
A seasonal toy wholesaler runs a debt sweep against its overdraft. Between August and November the account is heavily drawn, and from January the sweep automatically repays the facility as cash comes in, cutting interest without anyone monitoring the balance.
Example
A property group with nine subsidiary companies moves to a notional pooling arrangement. Three companies routinely sit in overdraft while six hold surplus, and pooling the balances removes about $54,000 of annual overdraft interest across the group.
Think of it
“A sweep account automatically moves excess cash to earn interest-like auto-transferring to savings.
Formula
Calculation
Annual benefit = average swept balance x (rate earned on swept funds - rate earned on current account) - fees
A dental group keeps an average of $1,200,000 above its operating buffer. The current account pays 0.25% a year, while the bank's money market sweep pays 4.25%, and the bank charges $500 a month to run the arrangement.
Interest gained = $1,200,000 x (0.0425 - 0.0025) = $1,200,000 x 0.04 = $48,000 a year
Annual fees = $500 x 12 = $6,000, so the net benefit = $48,000 - $6,000 = $42,000 a year, or $3,500 a month.
For a debt sweep the same balance behaves differently. If the group instead used the $1,200,000 to offset a revolving facility charging 7.5%, the saving would be $1,200,000 x (0.075 - 0.0025) = $87,000 before fees, which is why paying down borrowing usually beats earning deposit interest.Case study
Seen in the real world.
The following is an illustrative and fictional example. Fenwick Dental Group, an invented chain of 22 practices, held every practice's takings in a separate current account so that each manager could see their own balance. Across all 22 accounts the group averaged $1,900,000 of idle cash earning 0.1%.
The finance director set up a daily sweep into a single group money market account paying 4.3%, leaving each practice a $15,000 operating buffer and full visibility of its own trading through the reporting system rather than the bank balance. On $1,900,000 at a spread of 4.2%, the fictional arrangement produced about $79,800 a year of new income for no operational change.
Fenwick also discovered a second benefit that the illustrative numbers do not capture. Because the sweep required an agreed buffer and a daily cash view, the group started forecasting cash weekly for the first time, and stopped needing its overdraft entirely.
Watch out
Common mistakes.
- Setting the target balance too low, so the sweep drains the account and payments fail on the days when receipts arrive later than expected.
- Comparing only the headline interest rate and ignoring the monthly fees, which can wipe out the benefit on a modest balance.
- Assuming money swept into a fund carries the same protection as a bank deposit, when the legal position is often quite different.
Questions
People also ask.
How much surplus makes a sweep worth setting up?
As a rough guide, once the interest spread on the average balance comfortably exceeds twice the bank's fees, which for typical charges means balances in the high six figures.
Is it better to sweep into deposits or against debt?
Against debt in almost every case, because borrowing rates are higher than deposit rates, so a dollar of repayment saves more than a dollar of deposit earns.
Does a sweep account complicate the accounts?
Only slightly; the swept balance is still cash or a cash equivalent, but the treasury policy should state where it sits and who is authorised to change the arrangement.
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