Here, we take a closer look at the deal and investigate how it shapes up in comparison to other fixed-rate accounts - as well as ISAs offering easy access to your cash.
What's the deal?
Halifax is keen to woo savers looking for a new home for their ISA funds in the run up to the end of the 2013/2014 tax year. To that end, it has launched a new 18-month fixed-rate ISA paying a market-leading tax-free rate of 2.00% on £500 or more.
Richard Fearon at Halifax said: "Our new 18-month ISA gives customers a market-leading interest rate as well as the freedom that comes with a relatively short savings term."
The account accepts transfers in from other ISA providers, while savers can now choose whether they want their interest to be earned annually or monthly. Furthermore, account-holders with balances of at least £5,000 qualify for the Halifax Savers Prize Draw, which means they are automatically entered into a monthly draw to win up to £500,000.
And, like all Halifax ISAs, the account is also covered by the Halifax ISA Promise, which states that you will start being paid interest on the day your application is received.
Who is it good for?
This new 18-month ISA from Halifax offers a good compromise for those looking to receive a high interest rate without giving up access to their money long term.
The fact that you can make transfers in from other accounts and opt to receive your interest monthly is likely to make it particularly popular with savers looking to boost their income with the interest from their ISA savings.
"Customers have the option of receiving interest every month instead of annually, which will help those using their interest as income," said Richard Fearon.
The £500 minimum opening amount on this account makes it accessible to first-time ISA savers. However, all deposits must be made within the first 60 days, making it unsuitable for anyone hoping to add regularly to their ISA funds.
Other catches include that no withdrawals are allowed within the 18-month term. If you need to close the account before the 18-month term comes to an end, you will lose 135 days of tax-free interest.
Finally, fans of internet banking may be disappointed to learn that the account can only be managed over the phone or in Halifax branches.
What's the verdict?
The new 18-month Halifax ISA Saver Fixed has lots of plus points. Not only is it the market-leading account over this timeframe, it offers the same rate of interest as many of the two-year accounts on the market and pays just 0.05% less than Halifax's own two-year ISA.
That said, there are some other competitive cash ISAs around - especially those linked to current accounts. Santander 123 current account or credit card customers, for example, can apply for and transfer funds from other accounts to a two-year fixed-rate ISA paying 2.30% on £500 and above.
And Co-operative Bank and Smile customers may qualify for Britannia's fixed-rate ISA lasting until January 31, 2016, and paying a fixed rate of 2.20% on £1 upwards.
If you want an account that offers more immediate access to your ISA savings, it is worth checking out the Islamic Bank of Britain's Sharia'a compliant Notice Cash ISA at 1.80%.
This market-leading account accepts transfers from other providers and is open to anyone with at least £250 to invest. You can withdraw money penalty-free when you give 120 days' notice.
Please note: any rates or deals mentioned in this article were available at the time of writing. Click on a highlighted product and apply direct.