The sales figure resulted from a record number of customers buying Unicom's services - more than 68,000 invoices were issued in the month, almost 10,000 up on May 2007, reflecting industry-beating retention rates and a relentless demand for what the company provides.
"Consolidation in the telecoms marketplace has tempted some of our competitors to increase their prices but this merely assists both our new sales and our retention rate, each of which is heading in a favourable direction," said Tony Eagleton of Unicom.
"The telecoms sector annual average retention rate is around 70%. Of the 14% we lose, only a third go to competitors, the remainder being businesses that close or move premises for one reason or another, which is obviously beyond our control.
"We get off on the right foot with our new customers because, while we are looking to the future in terms of raising our standards of delivery even higher, it's something from the past that they really like: a 'normal' 0161 phone number, and UK-based people answering incoming calls in less than six seconds.
"We provide our customers with highly competitive prices, which we fix for three years, and we strive to ensure that all customers genuinely receive the highest possible levels of customer service.
"We're a relatively small business with a small, closely-knit and efficient management team - and we are absolutely clear in our minds about what makes the difference to our customers: a UK call centre with real people answering the telephone, 98% of calls answered within six seconds, and managers and directors who are hands-on and accessible."
Unicom reported a 13.5% increase in sales and a 23.6% rise in profits to the end of April 2008, its ninth trading year.
Unicom, which has a regional headquarters in Newcastle-upon-Tyne, saw turnover increase from £36.7 million to £41.6 million, with pre-tax profits at £9.5 million compared to £7.7 million to the end of April 2007.