Charlie Mullins is the UK’s wealthiest plumber. It took the Londoner a while to appreciate what he could buy with the number of digits in his bank account. ‘I think it was only four to five years ago when I realised that I could afford to buy these things,’ he reflects.

The things in question are celebrity memorabilia. Some of the most expensive items in Mullins’ collection include an autographed picture of Princess Diana, signed David Beckham and Wayne Rooney football shirts and Rat Pack photos. He estimates the collection has cost him at least £100,000.

p>‘If I’m being honest, I bought all these things because they remind me of the fact that I couldn’t have had them years ago. So it makes me think I have done the right thing, because I have things other people don’t. That does give me a bit of a buzz,’ he concedes.

Mullins’ story is your classic rags to riches tale. Wanting to be a plumber since the age of nine, the Londoner would bunk off school to work with the local plumber for ‘two bob a day’ – having spotted early on an escape route through the trade.

‘[The plumber] was the only person I knew who had a car and went on holiday – the only person in the area that had any money. When you arrived on a job with him people would give you tea and biscuits. The whole thing seemed like another world to me. I’d go around with him for the whole day and it felt as if I was being treated like royalty. Everyone respected and welcomed him.’

Passport to pimlico

Mullins left school at 15 to do an apprenticeship and was self-employed at 19. ‘I moved around different areas and eventually settled in Pimlico as there was a lot of money around that area.’

The company has been going for 30 years, but its success started to soar following the last recession. ‘We don’t turn up late. We wear smart clothes and are transparent with our prices. These aren’t things people normally associate with plumbers.’

Now Mullins has a roster of celebrities on his books, including the likes of Michael Winner, Chris Tarrant, Britt Ekland and Sophie Ellis-Bextor – to name just a few. However, he remains surprisingly underwhelmed by his A-list clientele.

‘Hmmm, I’m not sure who I was most pleased to meet. Maybe Max Clifford, although I know he’s also my PR.’ When asked what Chris Tarrant was like Mullins remains equally matter of fact. ‘He’s all right. A bit of a mickey-taker to be honest. Quite sarcastic, which can be funny depending on which side of it you’re on.’

The same non-committal tone is echoed when Mullins talks about the favourite pieces in his collection. ‘Possibly the Diana photo. It’s not something my wife would let me sell.’ And despite all the signed shirts, he admits to being ‘no great football fan’.

As for other items that have taken Mullins’ fancy, he notes a personalised number plate that spells “Water” for £29,000. ‘I got that very much for the same reason as the other stuff,’ he comments. ‘Without it, I wouldn’t be in a position to be talking about the nice lifestyle I’m fortunate enough to have.’

In fact, Mullins has spent £1 million on his 80 number plates spelling out plumbing-related themes. Others include “Drains”, “Sinks”, “Shower”, “Gas” and “Loo 2 Rod”. But he says they are an investment in the business as he uses them on his vans and is looking to acquire another 40 for the rest of his fleet.

‘It gets us noticed,’ he says.