With 5 April not far away, we’ve asked our contact team to answer all the questions they’re asked about ISAs and paying in before the end of the tax year.

This article is here to help you understand ISAs and how to pay in if you want to – but it’s not a personal recommendation to do so or financial advice. You should make your decisions on what’s best for you and consider financial advice if you’re not sure.

Keep in mind that ISA and tax rules change and that any benefits will depend on your circumstances. The features and rules of ISAs outlined here are for the 2023/24 tax year – and are due to change from 5 April 2024.

What is an ISA and how does it work?

Put simply, ISAs are a way to save and invest while protecting any money you make from UK tax.

When you have savings or investments in an ISA, there’s no income tax to pay on any dividends or interest, and no capital gains tax to pay if you make a profit on your investments. This means you get to keep any money you make (although returns on investments aren’t guaranteed).

And with a Triodos ISA, you can be confident that your money or investments are supporting environmental and social causes.

What types of ISAs are there?

You might have heard of cash ISAs already. These are savings accounts where any interest that you earn is tax-free.

The Triodos Online Cash ISA is an easy-access account which lets you take money out whenever you like. There’s also a Fixed Rate Cash ISA which aims to pay a higher interest rate, but you would need to leave your money until the end of the term to receive it.

ISAs aren’t just for savings. Despite the name (Individual Savings Accounts) there are also ISAs designed for investments.

Triodos offers two different types of ISAs for investments: There’s the Stocks and Shares ISA which allows customers to invest in sustainable listed companies via our impact funds, and the Innovative Finance ISA allows customers to directly invest in organisations via the crowdfunding platform.

Keep in mind that investments aren’t like cash savings, they change in value over time based on how well the investment is doing. Depending on the value when you sell, you could get back less than you put in.

Is investing right for me?

There are other types of ISAs, such as the Lifetime ISA which aims to assist with saving and investing for later life or a first home purchase, but Triodos does not offer these.

How much can I put into ISAs?

You can put up to £20,000 into ISAs each tax year. You don’t need to pay UK tax to open or pay into one, but you must be a UK resident. If you don’t use your current tax year's allowance, you lose it. The £20,000 allowance resets every tax year on 6 April and any unused allowance will not be carried over.

If you’ve got a Junior ISA for a child, the allowance for this is £9,000. It's not currently possible to open a new Junior ISA with Triodos, but we can accept payments into existing ones that are already open with us.

Can I pay into different ISAs in the same tax year?

The good news is that you can split your ISA allowance across different types of ISA. So, for example, you could pay into a cash ISA, a Stocks and Shares ISA and an Innovative Finance ISA, all in the same tax year – providing you don’t go over the £20,000 allowance.

This means that you can create your own mix of tax-efficient savings and/or investments, depending on what’s right for you and the kind of impact you want to make.

But what you can’t do (at least for the 2023/24 tax year), is pay into two ISAs of the same type. For example, if you decide to pay into a Triodos Online Cash ISA this tax year, you can’t also pay into a Fixed Rate Cash ISA, as these are both cash ISAs.

I’ve got ISAs with other companies or banks, can I open one here?

Yes, you can have different ISAs with different providers. Keep in mind though the rule mentioned above: you can’t pay into two ISAs of the same type in the same tax year. So, for example, if you’ve paid into a cash ISA elsewhere this tax year, you can’t pay into a cash ISA with Triodos.

This rule is set to change from 6 April 2024, giving ISAs even more flexibility.

Do I need to declare my existing Triodos ISA before paying in?

If you have an existing Triodos ISA but haven’t paid in since 5 April 2022, you’ll need to declare your ISA eligibility before paying in. You can do this by logging into Internet Banking via our website – it’s not currently possible to do this via the Triodos Mobile App.

Once you’re logged in, go to 'Self Service’ and then ‘Account Settings’. Select your ISA account from the drop-down menu and then ‘ISA Declaration Management’.

If you don’t use internet banking and you have a Cash ISA, you can download a Cash ISA declaration form and send it to FREEPOST Triodos Bank.

This is another rule which is set to change from 6 April 2024. ISA customers won’t need to declare their ISAs again from this date. Once they open an ISA, it stays open until they decide to close it.

How do I pay into my existing Triodos cash ISA?

The easiest way is to make a payment by bank transfer from another account. You can make this payment from another bank or building society account you have, or from another Triodos account that allows withdrawals (such as the Triodos Personal Current Account).

The Triodos Bank sort code is 16-58-10. You can find your Triodos ISA account number by logging in to your account online or via the Triodos Mobile Banking App, or by checking your bank statements.

If you want to deposit a cheque, please post it along with your account details or a paying-in slip to: ‘Freepost TRIODOS BANK’ (no stamp required). Be aware that the Online Cash ISA and Fixed Rate Cash ISAs do not accept cheques.

How do I add money to my Stocks and Shares ISA?

Every Triodos Stocks and Shares ISA has a linked Cash Account which you can add money to. When you pay money into this Cash Account, it will count as an ISA subscription for the current tax year.

You can find your Cash Account bank account number within the Triodos Mobile Banking App or Internet Banking, use this along with our sort code 16-58-10. But you might have more than one Cash Account (for example, if you have a Stocks and Shares ISA and Impact Investment Account), so make sure you get the right one.

You will see your Cash Account coupled next to the Stocks and Shares ISA it is linked to, in your account ‘Overview’ in the Mobile App or Internet Banking.

If I add money to a Stocks and Shares ISA now, do I have to invest straight away?

No, you can invest it whenever you like. Any money you add by 5 April will count as an ISA subscription for the current tax year, but you can invest it at a later date. Even if you invest this money in the new tax year, it won’t affect your new £20,000 ISA allowance.

Remember though that the money added to the Cash Account isn't invested automatically. You need to place the investment instructions yourself. 

There is no interest on cash held in the Triodos Stocks and Shares ISA or Triodos Innovative Finance ISA. Therefore, you should only add money to your wallet or cash account if you intend to invest it soon. Otherwise, you may be better off putting the money in a cash ISA where it can earn interest while you wait, and transfer later.

How to buy shares 

When do I need to pay in by to ensure my ISA subscription counts for this tax year?

Although the tax year ends at midnight on 5 April, your payment will need to reach us before then to ensure it’s processed in time. It’s a busy time for the bank, so we encourage you to make a payment as early as possible.

You can find our ISA deadlines and how to top up by visiting the ISA page on our website.

ISA deadlines and how to top up

How do I open a new ISA?

Before you apply for an ISA, you need to read all the relevant information on our ISA webpages (including the important documents) to make sure you're comfortable that it's right for you. Once you're happy, you'll need to select 'apply' on the relevant ISA webpage to begin your journey.

As part of opening a Triodos ISA, you'll need to download the Triodos Mobile Banking App (if you don't already have it). It’s simple, secure and takes less than 15 minutes. Once you have applied, we will get your account up and running as quickly as possible.

We aim to provide you with information to help you make well-informed decisions about your finances, but keep in mind that it's not advice.