App-based savings that don’t just grow. They help others cut carbon too.

Save your pocket and the planet

Kat, 28
Kat's First Car Fund hit £5,000
Automated savings sorted Paris trip 
Found ways to reduce her flat's energy bills
Dave, 62
Dave’s Holibob Saver raked in £67.88
Car emissions? Looking greener
His savings helped fund solar panels (legend)
Mina, 48
Mina's Saver banked another £45
Car loan? Pre-approved!
Helped insulate a home by locking funds away
Moneyfacts
Best App-Only
Savings Provider
2024
Moneyfacts
Voted Best
Customer Service
2024

The Cash ISAs you’ve been waiting for are here!  

Earn up to 
25
% AER, tax-free.
Savings Accounts

Save a little greener

When you save with us, your deposits don't just earn interest. Some help finance greener choices for others, from solar panels to electric vehicles. Feels pretty good, huh?

Cash ISAs

Still got some of your tax-free ISA allowance left? Or want to move it over to us? These are the ones to go for.

Instant Access Cash ISA
Variable rate
50
% AER
with top-up bonus
Best for tax-free savings you can dip into anytime.
Monthly interest
24/7 access to your funds
Includes bonus top-up rate
Fixed Rate Cash ISA
Fixed rate
Up to 
25
% AER
Best for tax-free savings you don't need to touch
Fixed monthly interest
Funds locked for the full term
Early withdrawal penalty applies

Savings Accounts

Already used up your ISA allowance? You can still earn interest with these accounts.

Instant Access Saver
Variable rate
3.65
% AER
Best for easy-access savings once your ISA allowance is used.
24/7 access to your funds
Unlimited withdrawals and deposits
Variable interest rate
Fixed Term Saver
Fixed rate
Up to 
4.2
% AER
Best when your ISA’s maxed and you’re saving for something bigger.
No withdrawals during the term
14 days to fund your account
Guaranteed return over time

Helpful tip!

AER stands for Annual Equivalent Rate and illustrates what the interest rate would be if interest was paid and compounded each year. This allows you to compare easily what return you can expect from your savings over time.

Brian's Europe Trip
1 Year Fixed Rate Cash ISA
£3,000.00
Unlocked
2 days left to deposit
Locks  10 Nov 2025
Emergency Fund
Instant Access Cash ISA
£500.00
Loans

Borrow a little greener

From buying a home to upgrading your car,  we've got finance options, available exclusively through brokers and partners, to steer you towards greener choices. Because let's face it, we could all use a little nudge in the green direction.

Buying a house?

A mortgage that rewards your greener lifestyle? Yes, please. Unlock rate discounts for more energy efficient homes rated A-B.

Need a loan for something big?

Whether it’s revamping your space or consolidating debt, unlock a rate discount if your home is more energy efficient.

Making your home more efficient?

If you’re thinking about making upgrades at home, our trusted partners could help you boost efficiency and shrink your carbon footprint.

Thinking about a greener car?

Whether that’s an EV or a lower emission vehicle, we’ll help you get on the road with loans available through trusted dealerships.

38%

Of our lending in 2024 went to greener upgrades. Your savings help make that possible.

Your home's energy rating
A
99
Excellent
The Impact

Here’s what your savings have helped power — and we’re only getting started.

01

160,000

People taking greener steps

That’s how many customers we’ve backed in making their homes more energy-efficient, from better glazing to cleaner heating systems.

02

£700m+

Lent to decarbonise UK homes

We’ve used your deposits to fund upgrades that help people cut energy use and carbon emissions.

03

70,000

Tonnes of CO₂ saved in 2024

That’s the equivalent of taking more than 15,000 petrol cars off the road for a year.

Based on UK government estimates of ~4.6 tonnes of CO₂ per car per year.

Never heard of us?

We’re a fully regulated UK bank. Just one built for the planet, not paperwork.

Ready to save more than just money?

Download the Tandem app
Open an account
Start growing your money
AWards and Reviews

That's enough from us, hear it from those who matter

See what others have to say
Join 150,000+ on the app
Moneyfacts
Voted Best
Customer Service
2024
Best app-based savings provider

Can't find what you're after?

Check out our FAQs for answers to your burning questions, or give our friendly support teams a shout.