CHARLES DUNSTONE is not hung over. “No, surprisingly not,” he chuckles, “though there are a few people round here looking a bit red-eyed, I think.”

It’s the morning after the mobile-phone trade’s big awards evening, a bash compered by Lenny Henry at the Hilton Hotel in London. Dunstone’s company, Carphone Warehouse, won “best retailer” for the ninth year running.

Sitting in his west London office, surveying the walking dead around him, Dunstone says that, normally, he would have tanked it back, too.

Not any more. He has meetings in the City, a busy day — oh boring. And despite the firm’s record of winning, he still finds such ceremonies nerve-wracking. “The awards are ours to lose now, aren’t they?” he sighs.

But then he was always a worrier. Even in a good week — and last week was a very good week for Dunstone — he seems to have little anxieties popping up all over the place. Yes, he announced to the City that Carphone will pay its first dividend later this year. Yes, he revealed it is making very good progress with its launch into residential fixed-line services. Yes, his ever-growing chain of shops (more than 1,100 across Europe) is still garnering awards and, in the first week of the Gulf war, even saw a jump in sales.

But there are always the niggles. Like the “sell” recommendation put out on Carphone shares by Merrill Lynch after Monday’s announcement. “And they were ‘buy’ when everyone else was saying ‘sell’. I think they just want to be contrary,” he says. Dunstone, 38, usually one of the most amiable bosses in British business, is suddenly perplexed.

This is how he operates, veering between charm and caution, always trying to understand what people are thinking, what will persuade them to buy into his proposition, and rationalising around the problems. Then he moves fast to cash in. It’s how he built up Carphone from a single sales outlet funded by his £6,000 savings, and how he developed the marketing nous that is now switching his firm from selling products to providing services.

And you would never think, if you met him in his trademark chinos and checked shirt, that since floating the company three years ago he has been one of the richest young men in the country. That’s how he likes it. Mousy-haired, short, chubby, worried about his weight — the carbohydrate’s the problem, he says, the more tired he gets, the more he packs in to refuel — Dunstone has a salesman’s knack of always pitching a level below the guy he is selling to. Sometimes, though, you have to read between the lines.

His softly-softly move into residential fixed-line services, for instance — 31,000 subscribers signed up to Carphone’s Talk Talk service since February with virtually no marketing — has got City noses twitching. Changes pushed through by the telecoms regulator last July mean BT has to allow competitors to offer rival services that don’t involve installing a dialer box or punching in a code before each call.

Walk into a Carphone store, sign up, and they do all the switch-over stuff for you, promising a reduction on your residential bill — average 25% — or you get £500. For consumers it should be, as one Dunstone adviser puts it, “a no-brainer”. For Carphone, it’s a market worth £8 billion. Supermarkets, credit-card firms and others are studying it closely. After Dunstone, the deluge.

Yet why, if he is first in, is he moving so slowly? It’s that caution again. “I want to understand what people’s objections might be, so we can refine our approach. It’s a big step to take for us, a leap in the minds of our customers. I just need to position it carefully.”

The big push is coming, he says, and the potential margins are very good. “The only cost is the call centre and the billing. BT still rents out the line and is responsible for repairs.” And Dunstone is not just thinking of running his own service, but hosting others too. The City knows he is talking to a big supermarket chain; he mentions a recent customer mailshot he received from Barclaycard . . .

Interested? “We’re talking to people,” he says, “and I think we’ll do deals.”

Dunstone has always been persuasive. His father Denis Dunstone, a former BP executive, remembers that even at the age of seven, “Charles could hold a dining table of adults spellbound with his telling of funny stories”. Likewise, at Uppingham public school, where Dunstone supplemented his pocket money by flogging mail-order desirables — with 100% mark-up — he convinced a gang of mates to sell for him.

His old schoolchum David Ross, who helped to build Carphone and is now its chief operating officer, describes Dunstone’s main skill as being “so personable” that he is always plausible. His real talent, though, has been in assembling at Carphone a team that complements his skills, and in turning what had been a group of public school “rugger buggers” into a thriving European business with a skilled, 8,000-strong, multi-ethnic workforce.

There are clouds on Dunstone’s horizon, however. Some investments in other firms haven’t worked out, and Carphone’s share price is still less than half what it was when it floated, leaving family, friends and employees potentially out of pocket. The same slippage between expectation and reality was cited by Sir Richard Branson as the reason why he took Virgin private again after an unhappy sojourn as a public company.

Could Dunstone do the same? No, he says. “Anyway, it would just crystallise everyone’s losses, wouldn’t it?” His explanation to staff is that it’s business, not personal — if they had put the money in a FTSE 250 tracker fund, it would have slipped the same. He admits ruefully that much of the £56m he made from the shares he sold on float was given to a fund manager to reinvest. He is now rather less rich than he was, though the £3m that he is due in Carphone dividend payments this summer should help out.

Anyway, he says he is not bothered about the money, he wants to avoid the ostentatious lifestyle of the mega-wealthy. He has a nice house in Holland Park, another in Norfolk, that’s all. Oh, and two large racing yachts. He adores racing — his “anaesthetic” to help him forget the cares of business — but there is a limit. He wrinkles his nose when I ask if he would ever consider joining Oracle’s Larry Ellison and competing in the America’s Cup, the yachting world’s most prestigious competition.

“Do you know how much an America’s Cup bid costs?” he says. He cites the $80m spent by the recent Swiss winner and some other figures. It seems he has studied them rather closely.

He would need to snatch more than a share of BT’s residential fixed-line market to put that together. “You’d have to know what you are doing, because the UK hasn’t been in the America’s Cup for so long, you would have to do three challenges . . .” For a second, Dunstone sounds rather wistful.