Isas that pay 5.05% and let you dip in and out are a good choice, says SYLVIA MORRIS

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Savvy savers know that cash Isa rates are on the rise, with providers competing for our habits in easy-to-access accounts.

Recent interest rate increases include Plum* at 5.01 percent, Money box against 5 percent and Chip* against 4.85 percent while Trading 212* now tops the tree with an exclusive rate of 5.05 percent for This is Money readers, including a 0.15 percentage point bonus.

It should be easy to get the most out of your money Isa, but it can be tricky and time-consuming to navigate.

There have been many rule changes since Isas was introduced 26 years ago. There are so many differences in what providers offer that you need to go beyond just looking at the rate to make sure it suits you and your lifestyle.

Is the bill flexible? Can you withdraw money when you want and how long does the highest interest last? Providers are not all the same.

Some let you withdraw money and replace it – as long as you do this in the same tax year – without affecting your £20,000 cash Isa allowance. Others don’t, despite government rules that say it is possible.

Your provider will tell you whether it is a flexible Isa or not, but you will often find the answer hidden in the terms and conditions.

Flexibility is key for savers who use their entire £20,000 Isa allowance each year. You can add and withdraw your savings during the year and receive tax-free interest.

For example, you could put in $10,000 during this tax year and then withdraw $3,000.

If your Isa is flexible, your remaining allowance is £13,000. If not, it’s £10,000.

If you want to switch from flexible provider to another, make sure you replace all the money you want before you move. The most important rule is that you must put the money back into the same Isa account you took it from.

Some cash ISAs allow you to withdraw money as often as you like, while others limit the number of times you can do this.

Isas may offer a bonus (which only lasts for a year), so you’ll have to move your money when time runs out or accept a lower rate.

Last week, Plum* increased the rate to 5.01 percent, including a first-year bonus that increases the rate from the base rate of 3.79 percent.

It limits you to three withdrawals per year. If you earn more, your rate drops to 2.5 percent.

Chip* has increased the rate for new customers to 4.85 percent, including a bonus paid for twelve months on top of the standard 4.58 percent.

Trade 212* pays 5.05 percent, a base 4.9 percent plus a 0.15 point bonus for new savers, with no withdrawal restrictions, only available through this special link.

In the meantime Money boxes 5 percent limits you to three withdrawals per year and includes a 0.55 percentage point bonus, payable for one year.

Chip and Trading 212 are both flexible Isas. Moneybox and Plum are not.

Some products from the major providers are not flexible Isas, including NatWest Cash Isa, HSBC Loyalty Cash Isa, Co-op (now part of Coventry BS) Cash Isa, Santander Easy-Access Isa and Virgin Money (now part of Nationwide) Defined Access Is.

Top rate online flexible Isas with no withdrawal restrictions Monument bank at 4.76 percent, but you need £10,000 to open an account.

Ford money pays 4.35 percent on £1 plus. In the main street, Newcastle BS Double Access Isa at 4.25 percent you are limited to two withdrawals per year.