McTear's, who believe they could be the first auctioneers to make the move, have launched the new system after they fell victim to a con last December which cost the firm a five-figure sum in jewellery, as well as another attempted fraud in that same week.
Brian Clements, who owns McTear's, told ATG that he would "absolutely" recommend other auctioneers to follow suit.
He finally made the decision to scrap phone payments after one fraudster started harassing his staff over a Rolex watch worth more than £6000.
"The guy ended up being really abusive to the girls in the office and I took the telephone over and said to him - I knew what was going on at that point - 'I'll refund it to your card', but he started reading off a number that was not anything to do with the card it had been paid with," he said.
"That essentially was that. We took a decision as a company not to take any payments over the telephone, by credit or debit card, because you are totally open.
"The only people that will lose are the auction house in this scenario.
"As a private indvidual, even if you've had your card stolen, or been careless about it, it doesn't matter, you're still protected, and the credit card company, they never lose. It is always the auction house that loses.
"It's at your peril if you take payments over the telephone for anything, and even with existing customers now we don't take payment over the telephone."
McTear's stopped taking such payments in January but didn't want to rely on bank transfers because the process can be cumbersome. This meant committing to online payments.
Any fears that scrapping phone payments might put some customers off proved unfounded, said Mr Clements. He has been delighted with the reaction so far, and says many people were, in fact, uncomfortable with reading out their card details on the phone.
"The reaction has been very, very favourable," he said. "I'm uncomfortable personally reading out my card number if I'm paying for something over the telephone, to a company that I might be dealing with on the first occasion. You are giving them all the details: card number, expiry date, name, three-digit code, so it's all there for people to use.
"I would say in terms of putting people off it is the contrary. It is actually a much securer way, not only for us but for the bidder.
"Ultimately their card details are going into a system we have access to, but they are completely safe - and really this kind of payment system is commonplace in internet purchases anyway, if you go and buy something at Amazon for example."
The auction house uses a system operated by a firm called Sagepay, which involves paying a fee, but Mr Clements said the overall start-up cost was about £400, a minimal sum in the context of the thousands that can be lost through fraud.
It had taken some time to arrange, though: "It is not an overnight set-up, it will take you at least several weeks to get it… not for the actual web design, that was done within a few hours, but getting hooked up, approval from card companies and so on, takes time."
But he says the online system has led to other cost savings in terms of staff time. "If we added up the hours in a week after a live auction with all the payments made by people far afield, and processing those payments, the time would run into days in a couple of weeks," Mr Clements added.
• the-saleroom.com, part of the same group that publishes Antiques Trade Gazette, provides auctioneers with an online payment system.
The system is fully integrated into the online toolboxes that the-saleroom.com provides to auctioneers and is fully Payment Card Industry (PCI) compliant.
When bidders register to bid at an auction on the-saleroom.com, they enter their credit or debit card details and where appropriate pass through 3D Secure.
An auctioneer using the-saleroom.com for live bidding can then process payments using a tokenised version of the bidder's card details.