I see merit in appointing Nets to deliver the unified e-payment system to serve 12,000 stalls at hawker centres, canteens and coffee shops (Nets to run unified e-payment system for hawker stalls; Sept 13).

Nets has been in the e-payment field for more than 30 years, with many customers.

Given the job to process virtually all small-sum transactions, Nets can help Singaporeans enjoy low transaction costs.

The all-in-one e-payment terminal is also a considerable engineering feat in integrating 20 types of contactless and chip-based cards, and processing QR codes.

As the unified system will displace all other terminals in hawker centres and small businesses, it may cause severe problems if this single system is down.

Here are some of my concerns:

Is the system secure enough to protect users? What if accounts are hacked, causing losses?

Will each transaction receive detailed receipts?

Will customers be penalised in case of system glitches or breakdowns and they are forced to pay with cash?

What if customers are not carrying cash?

Is there a contingency or parallel back-up system in case of system failures?

After three years of charging the initial 0.5 per cent transaction fee, will Nets continue doing so?

Paul Chan Poh Hoi