Since the article below was written, Santander have withdrawn their best deal Cash Isa's.

Santander have launched their new Isa offer's, which include an easy access Isa offering 2.5% to match the current, best rate, easy access Isa from Cheshire Building Society, (details of both below). Better again for savers interested in a fixed rate is the reintroduction by Santander of their "Major Isa" which proved popular last year. The new Major Isa 2 year fixed, offers savers a rate of 2.8 %, plus an additional 0.1% bonus if Rory McIlroy wins an eligible golf ‘Major’ (details below).

Santander are also offering it's 123 Current Account customers a 2 year fixed Isa paying 3%, with an additional 0.1% if Rory McIlroy wins an eligible golf ‘Major’ (details below). You must have, or take out, a 123 Credit Card to avail of the deal. This offer can be extended to those who choose to open a 123 Current Account and take out a 123 Credit Card with Santander.

Despite these last minute rate improvements, the fact is that most cash Isa rates offered are below the rate of inflation, currently 2.7% (Jan 2013). With any luck this fresh injection of competition into the Isa market by Santander may bring about a few more last minute deals from other banks/building societies.

For those with larger lump sums to invest, the cash Isa may still be an attractive option. But for smaller amounts, savers may be looking at the value to be had in regular savings accounts, rather than tying up their savings in low interest earning cash Isa's. Interest earned, even after tax is deducted, can often be more than what is offered by some cash Isa's. For example, First Direct's Regular Saver's Account offers 6% on savings; Nationwides Flexi Direct is paying 5%. 

The deadline for using up your cash Isa allowance of £5,640 is the 5th April.

Best rate Isa's which allow transfers from existing saving accounts

Cheshire Building Society 2.5% AER

• 2.5% variable rate including a fixed bonus interest rate of 2% until July 2014
• minimum deposit of £1,000
• unlimited withdrawals/deposits by post
• access is by post only, but can be set up online or by phone
• accepts transfers of existing Isa

Santander Direct Isa Saver  2.5% AER

• 2.5% variable rate including an introductory bonus of 0.50% for one year
• minimum deposit of £2,500
• unlimited withdrawals/deposits
• access online, by phone, by post, but not in branch
• accepts transfers of existing Isa

Halifax three-year fixed Isa Saver – 3% AER

• 3% AER for fixed term of 3 years
• minimum deposit of £500
• no withdrawals or additional deposits
• access in branch, by phone and online
• accepts transfers of existing Isa
• entered into monthly prize draw of up to £100,000

Santander Major Isa two year fixed - 2.8% AER (3% if you open/have a 123 Current Account with Santander)

• 2.8% AER for a fixed term of 2 years (3% if you open/have a 123 Current Account)
• Deposits for 2012/13 tax year can be made up to and including 5 April 2013 and deposits for 2013/14 tax year can be made up to and including 30 May 2013. No subsequent additional deposits.
• accepts transfers of existing Isa
• access in branch or by phone
• Additional one-off bonus of 0.10% tax free will be applied at maturity if Rory McIlroy wins an eligible golf 'Major' from April 2013 and April 2015

First Direct Cash Isa – 3% AER- only available if you have/open a First Direct current account

• 3% AER variable rate on balances of £40,000 and over. Tiered interest rates on balances below this amount
• you must hold/open a First Direct Current Account to avail of this offer
• minimum deposit of £1, but higher rate of 3% interest only on balances of £40,000 or over
• accepts transfers of existing Isa
• instant access by a transfer to another First Direct account
• access over the phone, by post or internet

HSBC online access only cash Isa -2.75% AER-  only available if you have/open a HSBC current account

• 2.75% AER variable rate cash Isa
• top interest rate only available on balances over £15,000, tiered interest rate on balances below this amount
• accepts transfers of existing Isa
• can only opened online, or by Isa transfer, but once opened, can be managed online, in branch, by phone or post.
• unlimited withdrawals/deposits