Easy-access pot
Interest builds every day on the balance you held the day before, and the app shows it as it builds. The short strokes under the chart are the interest itself, one for each day or week.
Easy-access, fixed and index pots for households
We print every rate before it moves.
Plainsum keeps your easy-access savings, a fixed pot and an index portfolio in one place. Every rate and fee carries a small number, and its terms sit just below, in type you can read.
PlainsumSavings projection
Sample figuresEasy-access pot after 5 years
£22,697.72
- Paid in
- £20,000.00
- Interest
- £2,697.72
| Year | Paid in | Interest | Balance |
|---|---|---|---|
| Year 1 | £8,000.00 | +£260.95 | £8,260.95 |
| Year 2 | £3,000.00 | +£394.65 | £11,655.60 |
| Year 3 | £3,000.00 | +£533.83 | £15,189.43 |
| Year 4 | £3,000.00 | +£678.73 | £18,868.16 |
| Year 5 | £3,000.00 | +£829.56 | £22,697.72 |
Assumes today’s variable 4.10% AER holds for the whole term, which it may not.
Rates, protection and press
Protection, regulator and press marks
Placeholders drawn for this sample. Plainsum is fictional and none of these bodies exist.
- Harbour Deposit Scheme
- The Conduct Register
- The Weekly Ledger
- MILLRACE
- Household Review
- The Rate Sheet
- Savers’ Forum
- NORTHGATE POST
- Easy-access pot, variable
- 4.10%1
- AER, builds daily and is paid monthly
- 1Variable. We give 30 days’ notice before any cut, and every change goes in the rate record further down. Interest builds daily and is paid monthly.
- 12-month fixed pot
- 4.45%2
- AER for a pot opened today
- 2Fixed for 12 months from your first payment in. Pay in £1,000 to £250,000 within 14 days. No withdrawals until the 12 months are up.
Saving and investing
Every pot shows its working.
Each Plainsum pot keeps its own sheet. The chart shows how the balance got there, and every movement is listed with its date.
12-month fixed pot
One rate for a year, set on the day you open it. Each month’s interest lands as a step, and the pot shows what it will hold on the day the term ends.
- Rate
- 4.45% AER for a pot opened today8
- Pay in
- £1,000 to £250,000 within 14 days
- Withdrawals
- None until the term ends
- At the end
- Renew, or move to easy-access
Index portfolio
One global index fund, bought on the 20th of each month. The dashed line is what you paid in; the solid line is what it is worth today.
- Charge
- 0.25% a year, all fees in9
- Holding
- One global equity index fund
- Buys
- Monthly, on the 20th
- Value
- Can fall as well as rise
PlainsumEasy-access pot
Sample accountBalance £8,412.60
Up £0.94 today, all of it interest
Earning 4.10% AER, variable
Recent activity
- Round-ups, 4 card payments22 Sep 2026+£2.31
- From your current account20 Sep 2026+£200.00
- To your current account12 Sep 2026−£150.00
- Round-ups, 1 card payment11 Sep 2026+£0.65
- Round-ups, 1 card payment10 Sep 2026+£0.10
- Round-ups, 2 card payments9 Sep 2026+£1.03
Plainsum12-month fixed pot
Sample accountBalance £5,160.39
Next interest on 1 Oct, about £18.14
Fixed at 4.30% AER until 1 Dec 2026
Recent activity
- Interest for August1 Sep 2026+£18.07
- Interest for July1 Aug 2026+£18.01
- Interest for June1 Jul 2026+£17.95
- Interest for May1 Jun 2026+£17.88
- Interest for April1 May 2026+£17.82
- Interest for March1 Apr 2026+£17.76
At the end of the term
£5,215.00
on 1 Dec 2026, if nothing is taken out
Renew for 12 months
Renews at the rate on the day.
PlainsumIndex portfolio
Sample accountBalance £8,166.60
Up £95.34 today, market move
0.25% a year, all fees in
Recent activity
- Monthly buy20 Sep 2026+£150.00
- Dividend, reinvested15 Sep 2026+£30.24
- Charge for August31 Aug 2026−£1.64
- Monthly buy20 Aug 2026+£150.00
- Charge for July31 Jul 2026−£1.68
- Monthly buy20 Jul 2026+£150.00
Charges in 2026
£12.20
- Plainsum, 0.15%
- £7.32
- Fund, 0.10%
- £4.88
Reinvest dividends
- 5Variable. The rate on 24 September 2026, the date of this sample. Interest builds daily and is paid on the 1st, and money you take out reaches your current account the same working day. The pots, balances, charts and activity on this page are sample data for a fictional product.
- 6Round-ups move at 6am for the previous day’s card payments, and a refunded payment keeps its round-up. Turn them off at any time.
- 7This is a projection. It assumes today’s rate holds, your £200 monthly transfer continues and round-ups keep this month’s pace.
- 8Fixed for 12 months from your first payment in, which must be £1,000 to £250,000 within 14 days. Nothing can be taken out before the term ends. A pot fixed before a rate change keeps the rate it opened with.
- 9Our charge is 0.15% a year and the fund’s is 0.10%. Investments can fall as well as rise, and you may get back less than you put in.
Year plates
Once a year, your savings draw their own figure.
Each January Plainsum sends a one-page summary of your year: what went in, what came out, the interest paid and the fees taken, in plain figures. At the top is a rosette drawn from those same numbers.10 No two members get the same one.
- TopJanuary sits at the top. The year runs clockwise, one lobe for each month.
- Upper rightMarch reaches furthest: £900 went in that month.
- Inner ringThe inner ring swells with each month’s interest, from £7.57 in January to £20.37 in December.
- Lower rightMay turns inward. £1,200 came out that month.
PlainsumYour 2025 summary
Sample- Paid in
- £5,150.00
- Taken out
- £1,200.00
- Interest paid
- £162.43
- Fees taken
- £0.00
- 10Year plates go to members whose pot was open for the whole calendar year, in the first week of January. The plate and the summary shown are drawn from a sample pot.
Rate notices
We tell you a month before a cut.Note 11
Plainsum writes to you in the app and by post, and names the reason.
PlainsumNotice, sent 1 May 2026
SampleYour easy-access rate is changing
Now4.25%AER
From 2 June4.10%AER
Down 0.15. On £8,000 that is about £12 less a year.
The base rate fell by 0.25 in April. We are passing on 0.15 of it.
- 1 MayNotice sent in the app and by post
- 2 JuneNew rate starts. Fixed pots keep theirs.
- 11Variable rates only. The notice goes out 30 days before the change.
Rate record
Every rate we have paid, kept on the record.
When a Plainsum rate moves, we write down the date, the size of the change and the reason. Nothing comes off this list.12
PlainsumRate record
Sample record| Date | Easy-access | 12-month fixed | What changed and why |
|---|---|---|---|
| 1 Sep 2026 | 4.10%, held | 4.45%, up 0.15 | Fixed up 0.15 as longer-term market rates rose. |
| 2 Jun 2026Notice sent 1 May | 4.10%, down 0.15 | 4.30%, held | Easy-access down 0.15 after the base rate fell. We wrote to every saver on 1 May. |
| 2 Mar 2026 | 4.25%, held | 4.30%, held | Reviewed and held. No change to either rate. |
| 1 Dec 2025 | 4.25%, held | 4.30%, down 0.10 | Fixed down 0.10. Pots already fixed keep the rate they opened with. |
| 1 Sep 2025 | 4.25%, down 0.25 | 4.40%, down 0.20 | Easy-access down 0.25 and fixed down 0.20 after two base-rate cuts over the summer. We wrote to every saver on 1 August. |
| 2 Sep 2024 | 4.50%, held | 4.60%, held | Launch rates. |
Rates since launch, as AER. A sample record for a fictional product.
- 12AER shows what the interest would come to over a year if it were paid and added each time. Pots fixed before a change keep the rate they opened with.
A saver’s view
A saver’s view
“I used to get one letter a year about my savings, and I never really understood it. Now yesterday’s interest is there every morning, and when the rate dropped in June, I had already read why.”
