These blockbuster savings rates are worth buying, but don’t miss deals that are disappearing quickly, says SIMON LAMBERT

Just when we thought savings rates were falling, along came some absolute humdingers.

Santander has this week unveiled a new 5.2 per cent easy access account, following last week’s 6.2 per cent NS&I blockbuster.

Both were good enough to rise to the top of This is Money’s independent best buy savings charts and certainly seemed to resonate with readers as our articles on both went straight to the top of This’s most read chart is Money went.

Fortunately, both the NS&I Guaranteed Growth Bond and the Santander Limited Edition Easy Access Saver are still on offer, but be warned that such high rates can disappear quickly.

Santander’s even includes a clue in the name that it won’t be on sale forever – that Limited Edition label hints at the fact that it will only be on sale for a fortnight, until September 17th.

And if it proves popular, there’s a chance it could be withdrawn before then.

Luckily for our readers, we offer a service that means you won’t miss any good bills. These Money’s Savings Alert emails will send you our stories about the best savings rates.

In a resurgent savings market, this is a great way to find out about the really best deals as they come in.

It is crucial that you must register for the Savings Alerts. It is an extra service and you will not receive it automatically just because you receive the This is Money newsletter.

You can find out how to sign up for Savings Alerts here or use the box below.

Now that the shameless Savings Alert plug is over, it’s time to get back to those rates: how good are the deals and does this flurry of activity at the top of the tables mean there’s more to come?

In my opinion, the NS&I Guaranteed Growth Bond is a great deal. A guaranteed return of 6.2 percent over one year is nothing to sneeze at and will probably beat inflation relatively quickly.

You can put up to £1m into that and it’s government backed, so there’s no worries about the £85,000 FSCS compensation limit that big savers have elsewhere.

There are a few catches: unlike with an Isa, you are taxed on savings interest and you cannot access your money for a year.

Santander’s Easy Access Saver of 5.2 percent also looks like a great offer. You can open it with as little as £1, deposit up to £250,000 (note the FSCS protection limit) and access your money instantly, with no limits on the number of withdrawals you can make.

However, that rate of 5.2 percent only applies to the annual interest. If you want monthly interest, the rate is 5.08 percent. And don’t forget to jump ship if you’re in a slump a year from now.

Whether this dynamic savings duo is a signal that the market is heating up again – with a return to the wave of rate hikes we saw at the beginning of the summer – remains to be seen.

That race to the top took place during the inflation panic that raised expectations for base rates and caused a mortgage spike. The moment of peak panic appears to be over and while base rates are expected to continue rising, things are more subdued.

A rate that isn’t as high, but offers protection against tax, was also introduced this week, with Moneybox’s 4.65 per cent cash Isa rocketing to the top of the tables.

Nevertheless, both accounts highlight why you should keep an eye on your savings and move your money around.

I tested how quickly you can do this over the summer and opened an account with app-based and FSCS secured Chip*which has consistently topped our savings tables and currently pays out 4.84 percent.

It took me just over five minutes to download the app, open an account and get money into it.

There are still many banks that charge savers on old accounts with an interest rate that is well below 2 percent. Don’t let your bank take advantage of your apathy, buy a better savings account instead.

*This Chiplink is an affiliate link. That means if you follow it and open an account, This is Money will earn a small commission. Such income makes the site free to use. We will not allow this to affect our editorial independence, nor will it affect the interest you receive.