Banks and building societies are fast to offer best buy savings accounts – but they pull them just as quickly.

Many only last a week or two, and sometimes just a few days, before they are swamped with demand from savers hungry for a decent return on their cash as inflation rages.

Providers have now resorted to hiking rates by a tiny amount just to claim the glory of offering a market-leading rate.

On April 17, United Trust Bank announced that it was cutting the interest rate on its five-year bond from 4.65 percent to 4.60 percent.

Then two days later, it lifted this rate by single basis point to 4.61 percent, simply to gain an edge over rival Tandem Bank, which was paying 4.60 percent via savings platform Raisin.

Now another odd trend has emerged.

Traditionally, savers are rewarded with a higher rate of interest if they commit to locking their money away for a longer term such as five years.

Yet Anna Bowes, savings expert at rate tracking service Savings Champion, said it's a different story today, as banks and building societies anticipate that interest rates will fall in the next year or so.

This means they reluctant to offer sky-high five-year fixed rates running to 2028, by which time interest rates could have fallen below one percent again.

Charter Savings Bank is the next best two-year fixed rate bond paying a guaranteed 4.62 percent a year, but on a higher minimum opening balance of £5,000.

This must be opened online but after that it can be managed by post or phone.

For those who would prefer to open and operate their account by phone or post, as well as online, Kent Reliance Building Society pays a slightly lower rate of 4.56 percent.

Bowes says most of the action today is in the short-term fixed rate bond tables, where plenty of competitive rates are being released.

But she suspects that five-year rates have now peaked: “The best longer0term bonds are actually paying a little less than a couple of weeks ago.”

Five-year fixed rate bonds are paying notably lower than last October, when United Trust Bank briefly offered 5.05 percent fixed for five years.

Savers who locked into that will be thrilled with their decision today.

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Yet now could still prove a good time to take out a five-year fixed-rate bond as rates could soon fall even lower, said Andrew Hagger, savings expert at MoneyComms.

“Inflation is forecast to fall sharply over the next six to 12 months and rates on longer term fixed-rate bonds could also fall as a result.”

By locking in today, you could potentially bag an inflation-busting rate once inflation and interest rates start to fall, boosting the value of your cash deposit in real terms.

But Hagger cautioned: “While you may see yourself earning more than inflation in a couple of years there's no guarantee that the economy may not play out as expected.” 

Last week's March inflation figure came as a shock and may tempt the Bank of England to keep hiking base rates. This is a dangerous move, though.

Base rate is currently 4.25 percent but markets expect the BoE to hike that to 4.50 percent in May, potentially followed by two more hikes to five percent.

Hagger said that even if you get a best buy rate, it's still won't pay anywhere near inflation. 

Yet it is still worth getting the best rate you can. 

Savers hold an estimated £273billion in accounts paying zero interest, and the spending power of those deposits is falling at an even faster pace as the cost-of-living crisis continues.

Doing nothing is the costliest option of all.