With booming sales in prepaid vouchers and international calling cards, retailers were unable to use their prepaid voucher terminal and separate EFTPOS terminal at the same time.

Mr Linc Burgess, chief executive of SmartPay Ltd, says because voucher pin numbers are stored in the terminal, the processing doesn't tie up the phone line for each transaction.

"This is a huge feature to many of our retailers who operate in busy environments and need to use their EFTPOS terminal and the SmartPay terminal at the same time. The flow on effect obviously is the whole sales process is speeded up for retailers as they don't have to wait until the line is free, and because the terminal is not dialing out it means the vouchers can be printed a lot quicker.

"The terminal only needs to dial out when it reaches a certain threshold and needs to refresh the pins stored in the terminal - this may only be once a day."

Allan Delaney, proprietor of PaperPlus Sunnynook on Auckland's North Shore says the technology solution is streamlining his business.

"We can serve our customers a lot quicker and the processing of prepaid sales is hassle free."

Delaney is able to print off multiple prepaid vouchers at any one time, providing quick turnaround of customers wanting prepaid product.

"It's certainly a much better alternative," he says. "We are a busy, seven day a week operation. The business in prepaid sales is pretty brisk. The last thing we want is having to wait behind the counter while the telephone line to our two EFTPOS machines become free."

PaperPlus Sunnynook switched to the SmartPay network two years ago because the company offered a few extra benefits, explained Delaney.

"SmartPay look after their customers very well and their response times to any queries we have is always excellent."