The cost of switching between home loans is likely to outweigh the savings.

State charges alone can be double or triple the difference between the most expensive and cheapest standard variable mortgages among the big banks.

Then there are exit fees for leaving a loan within the first four years, a separate discharge fee and another charge for setting up a new account, which all add up to more than $1000.

Consumer advocates and politicians on all sides of politics have called for some fees to be abolished to make it easier for borrowers to switch between loans.

A closer analysis shows Commonwealth Bank (CBA) customers would be unlikely to benefit from ditching their standard variable mortgage for a more competitive product.

The decision by Australia's biggest lender to increase lending rates by 45 points will see monthly repayments on an average $300,000 mortgage jump by $88 to $2,278 from Friday.

The CBA will have the dubious distinction of charging the most expensive interest among Australia's major banks.

By comparison, National Australia Bank (NAB) charges $112 less a month on an equivalent loan, charging 7.24 per cent interest.

Borrowers wanting to switch, however, would need to be mindful that state government land title office charges alone, of between $200 and $300, are already greater than the difference between the dearest and cheapest mortgages.

The major banks also charge an exit fee if a borrower wishes to switch out of a loan within the first four years.

ANZ and the CBA charge $700 while NAB and Westpac demand $900.

Only St George, owned by Westpac, doesn't charge a fee.

When it comes to charging a separate discharge fee, all the banks are on board.

St George charges the steepest fee of $500, and $1,000 if a mortgage borrower also has a deposit account or a credit card with the bank.

The bigger banks are also enthusiastic gougers, with the Commonwealth charging $350, followed by Westpac $250, ANZ $160 and NAB $150.

Starting up a new loan is also an expensive exercise, with the CBA charging an upfront fee of $750.

ANZ, NAB and Westpac charge $600 while St George levies a $700 fee.

Mitchell Watson, a financial analyst with Canstar Cannex, said borrowers were often better off seeking a cheaper mortgage product with their existing lender rather than paying hefty fees to change banks.