BT is turning off its internet dial-up service on 1 September.
BT told the BBC it was making the move as only a "tiny number" of customers used dial-up access, as the vast majority had access to broadband.
Dial-up customers were first informed about the end of BT dial-up in May and June. The telecoms firm admits about 1,000 customers in rural areas will not be able to get broadband as an alternative, as they live too far from a broadband phone exchange.
BT is currently being paid over £1 billion in government and council cash to deliver the rural superfast fibre broadband programme, designed to give homes and businesses in hard-to-reach areas a good broadband service.
Mark Pearce, strategic alliance director for network supplier Enterasys, said: “This news emphasises the digital divide between urban and rural businesses, leaving remotely located businesses falling further and further behind. Their limited connectivity limits growth and potential.
“This is bound to have a knock-on effect to the economy of rural communities, as businesses will no longer be able to base themselves where they cannot use high-speed broadband. Essential public sector businesses such as schools, colleges and hospitals will also struggle."
He said: “Shelving the out-moded dial-up service seems like a logical step in terms of progression. However, broadband services should be ready to take over to become the only form of internet connection, but they are not."
BT said those customers with no alternative broadband service would still be able to get an alternative dial-up service from its subsidiary ISP Plusnet.
"No-one is being left without the option of an alternative service," a BT spokesman told the BBC.
Ofcom figures in 2010 estimated there were still 800,000 customers on dial-up internet services, although this figure has been slashed since then with Ofcom no longer trying to measure the figure, as broadband availability and take-up has increased even further since the last dial-up estimate.