A little nutty. Entirely fictional. No real banking here ↗
AcornBank.

Current accounts · Products · FROM THE ACORNBANK FOREST

Overdreyft Buffer — Rates and Returns

A buffer, not a savings pot. The model applies interest only to the amount above £50 and shows what a shortfall costs over several durations. There is no real credit facility to draw on.

A bank card resting on a leaf ledger.
A fictional bank, a real sense of humour. All people, places, products and figures are invented. No real banking or financial advice. About this demo.

Demo rate card29.9% EAR (variable), with the first £50.00 interest-free

The pound values and percentages on this page are invented AcornBank product terms, chosen for a realistic bank-style example. They are not current market offers, an invitation to deposit or invest money or a forecast of what a real bank will pay.

Product detailDemo terms
Account typeArranged overdraft
Rate, reward or charge29.9% EAR (variable), with the first £50.00 interest-free
Illustrative credit limit£0.00 to £1,000.00
AccessUp to £1,000 arranged borrowing; the first £50 is interest-free in this demo model
Eligibility in the scenarioAn adult Acorn Everyday story customer with an assumed arranged limit
FeesNo model account fee
CurrencyGBP (£), used solely for fictional calculations

Try your own numbers

Change the amounts to see what Overdreyft Buffer would do in the story. Fictional figures, no application, no advice.

Interest for 30 days£9.7829.9% EAR on borrowing above £50.00
Interest-free portion
£50.00
If it lasted a full year
£134.55An overdraft is a cushion, not a loan.

Overdreyft Buffer against the rest of current accounts

FeatureAcorn EverydayNO MONTHLY FEE · NO INTERESTBranch Out Business£6 MONTHLY FEE · NO INTERESTOverdreyft Buffer29.9% EAR · FIRST £50 FREE
TypeCurrent accountBusiness current accountArranged overdraft
Rate, reward or charge0.00% credit interest; £0.00 monthly account fee0.00% credit interest; £6.00 monthly account fee29.9% EAR (variable), with the first £50.00 interest-free
Minimum£0.00£0.00£0.00

Overdreyft Buffer in charts

The same fictional model as the tables below, drawn rather than written. Hover or focus a mark for its value, or open the table view.

Cost of a shortfall by size and duration29.9% EAR, first £50 interest-free
  • 7 days
  • 30 days
  • 90 days
£0£20£40£60£80£50 · 7 days: £0.00£50 · 30 days: £0.00£50 · 90 days: £0.00£50£100 · 7 days: £0.25£100 · 30 days: £1.09£100 · 90 days: £3.33£100£250 · 7 days: £1.01£250 · 30 days: £4.35£250 · 90 days: £13.33£250£500 · 7 days: £2.26£500 · 30 days: £9.78£500 · 90 days: £29.98£500£1,000 · 7 days: £4.78£1,000 · 30 days: £20.65£1,000 · 90 days: £63.30£1,000

Constant borrowed balance; the EAR is converted to a daily equivalent.

View as a table
Category7 days30 days90 days
£50£0.00£0.00£0.00
£100£0.25£1.09£3.33
£250£1.01£4.35£13.33
£500£2.26£9.78£29.98
£1,000£4.78£20.65£63.30

How much could a shortfall cost?

Borrowed balanceAfter 7 daysAfter 30 daysAfter 90 days
£50.00£0.00£0.00£0.00
£100.00£0.25£1.09£3.33
£250.00£1.01£4.35£13.33
£500.00£2.26£9.78£29.98
£1,000.00£4.78£20.65£63.30

Assumptions: constant borrowed principal, no deposits, additional borrowing or fees; the first £50.00 remains interest-free. Estimated cost = max(balance − buffer, 0) × [(1 + 0.299)^(days/365) − 1]. This converts the illustrative EAR into an equivalent daily-compounding model and rounds only the final charge. It is an estimate, not a contractual daily posting schedule. An overdraft costs money; it does not produce a return.

Overdreyft Buffer is arranged overdraft in the Current accounts range, used for illustrating the cost of a short-lived current-account shortfall. Its live rate card, summary and worked tables sit above this text and update whenever the product record changes.

Understand the headline rate

Savings AER expresses annual interest including compounding where relevant; gross means before tax and tax-free means the demo ISA wrapper deducts none. APR and EAR describe borrowing costs on different stated bases. Cashback and 0% offers are perks on qualifying activity, not interest on a balance. Compare matching measures and read the assumptions below before comparing the numbers.

See the whole Current accounts range or compare every product on the rates page.

What the example does not promise

All figures are invented and shown to make the demo useful to read and crawl. No money is held, no application is available, and no deposit-protection, regulatory or tax-wrapper status is claimed. Calculations do not account for personal tax, inflation or unstated changes in rates. The fictional bank manager can guarantee only that the next paragraph contains no real acorns.

Related reading

AcornBank: entirely fictional banking, exceptionally committed squirrels.