Our savings correspondent, Lee Boyce, picks his five favourite cash Isas for savers in 2013 - essential reading to help you choose a top savings account for your money.
This page is kept up-to-date throughout the year - bookmark it for the very latest developments.
How an Isa works and why you should have one
Each year in April, savers are given a fresh Isa allowance that qualifies for tax-free interest.
For 2013-14, the limit has been set at £5,760 for cash Isas.
You can deposit anything up to this amount into a cash Isa until 5 April 2014.
However, the rules state that you can only contribute to one Isa per tax year, so choosing wisely is important.
You can also transfer an old Isa for better returns. Here's a quick guide to Isa saving.
Rates are low, but that just makes an Isa more important
At the start of the tax year, there is usually a mad dash from banks to grab savers cash and for this reason, there is a flurry of best buy deals available between March and May.
Sadly, in 2013, juicy deals have fallen away and experts believe that there won't be as much competition this year to offer as attractive rates in previous years.
Savers have been hit by a triple whammy in recent years - low interest rates, banks and building societies failing to match tax-free Isa rates to standard accounts, and the Chancellor’s refusal to date to allow them to put the whole of each year’s Isa allowance into cash.
To those injuries they can now add the insult of the Funding for Lending scheme that pushes £80billion of cheap cash through banks and building societies to borrowers and removes the incentive to offer decent savings rates to pull cash in.
Just five months ago, it was easy for savers to grab an Isa paying over three per cent. It is now difficult to obtain 2.5 per cent.
But low rates just make it even more important to shelter your interest from the taxman, which is what a cash Isa does.
More...
Can you find a better deal: Cash Isas, fixed rate Isas, regular savings Isas
What next for savings rates? Our expert on forecasting fixed bonds and variable deals
HOW TO PICK THE BEST ISA: Everything you need to know about cash accounts & stock market funds
Savers with pots scramble to avoid rate plunge: Five best cash Isa accounts that allow transfers in
How we pick our Isa favourite five
FIXED CASH ISA RATES
At present, only one fixed-rate cash Isas makes our top five list.
This is because the deals out at the moment only pay a slightly higher rate than easy-access Isas - and as such, tying up your money for a prolonged period of time could mean you miss out on top rates that come out in the next couple of months.
The highest fixed-rate is 3.1% from Halifax - but you'll have to fix for five years and will lose 12 months' worth of interest if you want to get out early. Savers need to ask themselves if that is worth it for an extra £60 per year interest on £10,000.
Check our Isa tables for all the deals available.
Due to overwhelming popularity, we decided to make a five favourite Isas round-up a permanent feature of This is Money.
So here it is, complete with an explanation detailing why we're happy to pick each account.
This page will be kept updated as and when new deals pop up or old ones get scrapped.
Remember, you can open an Isa or transfer (provided you're not tied to a fixed-term) at any time during the year.
Note that we don't just copy the best rates from the savings tables - we scour the market for all-around winners. This is a taster of the top deals. For the best rates, visit our savings rates tables, which are comprehensive and independently compiled.
Our favourite five
Nationwide Flexclusive Isa - 2.5% [Full details]
- Facts: Have to be Nationwide customer, 1% bonus
- Transfers in: No
- This is Money says: This account is only available to those who are Nationwide current account customers and have paid £750+ into their account for the last three months - or those transfer current account to the building society. It comes with a one per cent bonus until November 2014, can be opened with £1 and allows unlimited withdrawals. It doesn't accept transfers in.
Cheshire BS Isa Saver – 2.3% [Full details]
- Facts: Minimum £1,000 opening balance, unlimited withdrawals.
- Transfers in: Yes
- This is Money says: The rate includes a two percentage points until 31 October 2014. It allows unlimited withdrawals and transfers in from other providers. Can be opened online or over the telephone - however, it can only be accessed via post.
Principality BS Fixed Five Years - 3.1% [Full details]
- Facts: Minimum balance of £500, early withdrawals incur 360 day interest penalty
- Transfers in: Yes
- This is Money says: It's slim pickings on the fixed rate Isa front this year and savers need to ask themselves whether it is really worth locking up their cash for the minimal extra benefits. Ultimately, this year rather than being rewarded for locking cash away, savers are being protected against rates falling even further in the future. If you do like to lock up your money for the long-term, Principality Building Society's five-year fix is the best on offer.
Coventry BS Fixed Two Years - 2.55% [Full details]
- Facts: Accepts full Isa allowance only
- Transfers in: No
- This is Money says: Coventry BS softened the blow of pulling its easy-access 2.6 per cent Poppy Isa by replacing it with this two year fix. However, savers have to deposit £5,760 - the full 2013/14 tax-free allowance. You can open and run the account in branch, online, on the telephone or by post. The rate is guaranteed until 31 May 2015 while no partial withdrawals are permitted without penalty.
NS&I Direct Isa – 2.25% [Full details]
- Facts: Minimum balance of £1, no bonus
- Transfers in: No
- This is Money says: The variable rate Isa pays 2.25 per cent – and makes it into the list as other deals have slipped away. It comes without a bonus and you can make unlimited withdrawals. The account is accessed online or via the telephone.