Post Office ISAs are provided by OneFamily. Savings in Post Office cash ISAs are deposited with Bank of Ireland UK.
This guide is for general information only and isn’t financial advice.
What is an ISA?
Individual savings accounts (ISAs) are a tax-efficient way to save and invest. Any interest, dividends or capital gains earned on the funds you put in ISAs are exempt from UK income tax and capital gains tax.
There’s a limit to how much you can save in ISAs in a given tax year. The number of ISAs you can pay into in that time may be limited too. We’ll cover all this in the next sections.
Keep in mind that the tax advantages you receive will depend on your individual circumstances. The tax treatment may change in the future.
What are the benefits of ISAs?
People choose to save in ISAs for lots of reasons. These are some of the most common.
- Your savings aren’t taxed: This means you can maximise the return on what you save
- Choose how much you put in: You decide how much of your annual tax-free allowance you want to use each year. In the 2026-27 tax year, you can put up to £20,000 into ISAs
- No need to report returns: If you make money within your ISAs, you don’t need to report it on your tax return
In April 2027, the ISA limits are changing. If you're under 65, the maximum you can put in a cash ISA each year will be £12,000. The rest of the £20,000 allowance must be investments. If you're 65 and over, the £20,000 cash ISA limit will still apply.
Types of ISA
There are several different types of ISA.
Variable Cash ISAs
Variable Cash ISAs work a lot like regular savings accounts. The difference is there’s no tax on what you save. They’re low risk, so you make a modest return on your savings. The interest rate is variable so may change over time.
The tax advantages of variable cash ISAs depend on your individual circumstances. The tax treatment may change in the future.
Fixed rate ISAs
Fixed rate ISAs offer a guaranteed interest rate for a fixed period. You lock in your savings and know exactly how much interest they’ll earn in that time. You won’t normally be able to withdraw money during a fixed term. This can help you save money for a specific goal such as a deposit for a house.
Investment ISAs
Investment ISAs let you invest your money in assets such as stocks, bonds and funds. They offer higher potential returns over the long term. However, as markets can fluctuate, so might the performance of your investments too. So you could get back less than you paid in.
You don’t pay tax on the income and capital gains earned from those investments. They’re also known as stocks and shares ISAs.
Junior ISAs
Junior ISAs can give children a financial head start. Parents and guardians can open one on behalf of their children. The child receives the funds when they turn 18. They might use this for their education, a first home, travel plans or a big milestone. Cash and investment options are available.
Innovative finance ISAs
These ISAs let you invest in peer-to-peer lending or crowdfunding projects for potentially higher returns. Again, there are tax advantages. But the investments come with higher risk.
Lifetime ISAs
If you’re aged 18 to 39 and want to save for your future, a Lifetime ISA may suit you. It’s a tax-free way to save for milestones like your first home or even for later life, including retirement.
You can contribute up to £4,000 every tax year up to the age of 50. But the first must be before you’re aged 40. The government will also add a 25% contribution to these savings. That’s up to a maximum of £1,000 per year.
Choosing an ISA: which is right for you?
The right type of ISA for you will depend on your individual circumstances and your savings or investment goals. Consider a few factors before choosing an account:
- What interest rates do they offer?
- Are these rates fixed or could they change over time?
- Will you need access to your money?
- Or could you lock it in for a longer period to get a better, more predictable return?
- If investing some of what you save, how much risk will you tolerate?
Depending on your savings goals:
- If you want to withdraw your money any time, an instant access cash ISA may suit you
- If you’re comfortable with some risk, an investment ISA may help your money over time
It’s important to do your research. Make sure you compare different options before you decide where to save your money. And consider seeking independent financial advice before you invest.
You can read more about ISAS on the GOV.UK site or visit the Money Advice Service
Make the most of your tax-free savings allowance
Common questions about ISAs
-
You can put up to £20,000 in ISAs in the current tax year. The exceptions are Junior ISAs, which have a £9,000 limit, and Lifetime ISAs, for which it's £4,000. This may change in future years. Please check the GOV.UK guidance on ISAs for the most up-to-date information.
In April 2027, the ISA limits are changing. If you're under 65, the maximum you can put in a cash ISA each year will be £12,000. The rest of the £20,000 allowance must be investments. If you're 65 and over, the £20,000 cash ISA limit will still apply.
-
Yes, you can have multiple ISAs in a tax year if you like.
As of the 2024-25 tax year, these can be multiple cash ISAs, multiple stocks and shares ISAs, or a mix of both.
Lifetime ISAs are limited to one. Likewise, you can only open and contribute to one of each type of Junior ISA (one cash, one stocks and shares) per eligible child.
-
The level of risk depends on which type of ISA you open.
- Cash ISAs are generally low risk. You’re simply saving money in a tax-free savings account
- There’s more risk with investment ISAs. The value of your investments can go up or down
- The risk is higher with innovative finance ISAs as they involve peer-to-peer lending and crowdfunding
The greater the risk the greater the potential returns. So it’s important to decide upfront how much risk you’re prepared to accept before choosing which ISAs to open.
-
Yes. Junior ISAs let you put money away for your children’s futures. As a parent or guardian, you can open and manage a Junior ISA on behalf of your child. The funds become available on their 18th birthday.
-
Some providers, but not all, will allow you to transfer funds between cash, stocks and shares and innovative finance ISAs.
You can only transfer from a Lifetime ISA into another Lifetime ISA, and from a Junior ISA into another Junior ISA.
Transferring funds between ISAs won't affect your tax-free ISA allowance.
- Read more FAQs
-
This depends on the account. With some ISAs, you can access your money any time without paying a penalty. With others, there may be a penalty if you withdraw funds before the end of the fixed ISA term. Or the funds you withdraw may impact your remaining tax-free ISA allowance for that year.
Post Office ISAs for instance don't have flexible features. This means that once withdrawn, your money will lose the tax advantages of ISAs and cannot be replaced within the ISA without affecting your annual ISA allowance.
-
No. ISAs are exclusively for UK residents. If you move abroad, you can still hold and earn interest on existing ISAs. But you can't contribute into them.
-
The amount over the limit will be voided from the ISA in question. Any gain made on that amount will be taxable.
-
Yes. You can withdraw money from your ISA any time. There may be a penalty charge to do this early with some accounts. Check with your provider and the terms of your specific ISA.
Savings to suit you
-
Easy access savings
Keep your money somewhere safe, but withdraw whenever you like
-
Fixed rate savings
Saving for the longer term? Earn a fixed rate of interest for a set period of time
-
ISAs
Save tax-free with a fixed or variable rate of interest, or even both
More about savings
A guide to savings
Thinking of saving or investing, but don’t know where to start? This guide provides an introduction to the various options available.
How many ISAs can I have?
ISAs, or individual savings accounts, have been a popular way to save or invest your money tax-free for years. But how many can you open?
How much can I save in an ISA?
An ISA, or individual savings account, is a tax-free way to save or invest your money. But how much can you put in one each year?
Saving for a car
Buying a car is a big step, whether it’s your first set of wheels or an upgrade. But a good savings plan can help make it easier.
Saving for a rainy day
A rainy day fund can help make life's small surprises easier to manage. Learn how to build, manage and use a fund so you feel more prepared if something unexpected comes up.
Saving for a wedding
Planning your wedding should feel exciting, not stressful. Starting to save early helps you cover the cost of your dream day, avoid last-minute borrowing and make choices with confidence.
How to build an emergency fund: a savings guide
An emergency savings fund is your safety net for unexpected costs. This guide explains how to start an emergency fund, how much you need and why it’s so important.
What is a fixed rate bond?
Unsure about how fixed rate bonds work? We can help with that. In this guide, we’ll explain what fixed rate bonds are and how they can help your savings grow.