High Street banks have been accused of leaving some customers in "dire poverty" after taking money out of their accounts without permission.

Banks can move cash between different accounts belonging to the same person, and only have to tell them afterwards.

The practice, known as "setting off", typically involves banks moving money from a current account to pay off a credit card account which is overdrawn.

Citizens Advice says it has seen an 80% rise in inquiries about such transfers.

It is not illegal for banks to move money in this way. They only have to tell the customer after they have done it.

"Setting off" typically involves banks moving sums of between £100 and £200, usually to pay off a credit card account.

For many people that can actually be helpful, as it will save them interest charges.

I have no money for food, let alone for other essentials like washing materials”

Quote from John Gates

But for others, particularly those who receive benefits, it can cause serious hardship.

It pays to do the maths before switching from a variable rate mortgage.

If you're one of the two million people in Britain currently sitting on their lenders' standard mortgage rate, it can seem as if everyone is trying to tempt you away. First there are the blandishments of your current lender, whose seductive letters offering you other products especially selected for their loyal customers aim to drag you onto a higher rate. Even if you can resist these, you may fall victim to panic over interest rates, or special offers on new mortgages.

Now there's a new kid on the block, the loyalty mortgage. These products, offered by Santander, the Co-op, Halifax and Barclays, offer reduced interest rates to current account holders, mainly on two-year fixed mortgages. But is now really the time to take the bait and move off your deal? Make sure you do the maths first.

The party is over for borrowers with tracker mortgages

Being on your lender's standard variable rate – the rate that your mortgage reverts to when your deal ends – used to be a terrible idea financially. Recently, however, staying put has begun to look like a smart move. Many borrowers with Nationwide, Cheltenham & Gloucester (part of Lloyds TSB) and Barclays are on ultra-low mortgage rates with no penalties if they choose to move their mortgages elsewhere. Increasing numbers of them are choosing not to move, with Nationwide reporting that 38pc of its borrowers are on what it calls its Base Mortgage Rate (BMR), which is 2pc above Bank Rate.

That number has rocketed up from just 14pc in 2008 and it is costing the company money. Nationwide estimated that its guarantee not to charge more than 2 percentage points above Bank Rate for its BMR cost it £450m last year. "It would be unfair to say that we are trying to get customers off the BMR – it simply isn't true," a spokesman said.

But if a mortgage deal is costing your bank money, it is probably good news for you, which is why you should think very carefully before moving away from the rock-bottom SVRs available at present. If you are on one of them, or if your mortgage deal is coming to an end now, there are some serious calculations to do before deciding whether to go onto a new deal or to stay put. Consider the options before you even think about visiting a mortgage broker.

Millions of homebuyers are facing a 'mortgage timebomb' as lenders put up interest rates even though the base rate remains unchanged.

Experts are warning that lenders could hike their standard variable rate (SVR) at any time. 

Ten banks and building societies have already put up their rates, costing borrowers hundreds of pounds a year. 

This is despite the fact that SVRs are traditionally linked to the Bank of England base rate, which has been 0.5 per cent for 18 months. 

Culprit: Skipton Building Society hiked its SVR from 3.5 to 4.95 in March despite there being no rise in interest rates

The biggest culprit is Skipton Building Society, which hiked its SVR from 3.5 to 4.95 per cent in March.