Barclays says that, in the past, it would consider a change from capital repayment to just interest were a customer to ask for this.

With traditional mortgages, borrowers often face large penalties for additional capital repayments or if payments were not made on time.

The lender may place restrictions on the lending limits towards the end of the mortgage term with the aim of ensuring capital repayment.

They will lend against most types of property and offer a choice of capital repayment, endowment or pension linked mortgages.

Or no capital repayment until the end.

FIserve expects $23.5m from the offering and will use it for working capital, possible repayment of debt and acquisitions of complementary businesses.

Initially this means that the proportion of capital repayment is very small, but the proportion progressively increases throughout the period covered by the mortgage.

Other variations on possible repayment structures include a moratorium on capital repayments (and possibly also interest payments) for a period at the beginning of the loan.

- Fund recycling, both in terms of capital repayments and interest payments, enables funds to be re-invested in the future.

Mr. Kullberg, for example, said his capital repayment had been "probably a half-million bucks."