There is absolutly nothing sinister about a service company. Of course a 1 man band guy can operate through a Ltd company and only employ himself. Its simply a way to seperate the finances of a business from finances of a person. If you were self employed and something went tits up, and you got sued, or your business got flooded or something not covered by insurance, then they can only take what is owned by the Ltd firm, and not take away your family house.
As for trades people being a good route to avoid tax, not these days. I frequent trades counters of various suppliers, and anybody arriving in a van always has an account. Everybody has personal expenses these days that cant be paid in undeclared cash, such as a mortgage, car loans, pension payments etc. So you have to be able to declare at least that ammount of earnings. As for your business expenses, you'll have a yard, a van or two, maybe some rented equipment. All of that comes off before tax. HMRC knows what all the ratios of a well run business are. If a business stands out as having loads of business expenses but hardly makes a profit, they might look into the lifestyle of the business owner. If they appear flush with cash and have a lifestyle that seems beyond the declared earnings then they'll book you in for an interview, which 9/10 ends up as an investigation.
For proper tax minimisation, you really need to be earning the cash in a way that it can be banked abroad. So that can mean living in UK, but your company being registered in Guernsey for instance. Your offshore firm might own a house in which you live, and a car, and all the furniture. If you pick a good offshore locaton for the firm to be based, there won't be any issue with the rent free house being a taxable benfit either. Plus some of these offshore coutries have good secrercy laws, so the government can't even see how much the offshore firm makes or who owns it. All they would see if a guy living in a house rent free, declaring whatever salary they want to declare as bringing into to the UK to spend. If you intend to spend a lot of cash while out of the UK such as being on holiday, then that can be spent directly from the offshore account, no need to declare that to HMRC.
I think people think of being taxed as missing out on something, but at the end of the day, you just have to consider what the take home pay is and find a level that you are happy with.
If you really just want to avoid paying tax, then just look for professions that have special tax regimes. One such scheme that I think has been going since 1950s is seamens earning deduction(SED). Basically the government want to ensure that the merchant navy had british seamen on british boats so that if they were ever need in times of war then they could be called upon. So to encourage UK nationals to work in the fleet, theres a deal if you follow a few conditions then you pay no tax. So you have to have at least 1 forieng port call per year per employer, must be offshore out past the 12mile limit for 183 night a year, must get the captain to stamp and sign your seamans book. So although this is designed to retain the british marine crews on the UK fleet instead of being filled with russian or asians, there are some loop holes. A captain or chief engineer is basically as high as you can get and in the marine roles, but there a few very specialised roles on some ships, such as the boats that repair the fiber links that occasionally break in the middle of the ocean. There will be a few highly paid engineers onbard those ships that get double or triple a captains wage, and will be entitled to the SED. Some of the captains will grudge the fact that those guys also get the SED entitlement, but if those cable repair ships didnt exist then that captain wouldn't be on it earning his own wage.
Some british ex pats living abroad are in countries which don't have SED schemes. But they may have a reciprical agreement where for instance if you lived in France, you can file your tax in UK, and show the french a copy of the P60, and the french will then let you take that money into france without any further tax. So what you would do there is file your tax return in UK and not claim the SED, and get a P60 to show all the tax being paid. Then file an ammended tax return a year or so later(no more that 5) and claim the SED. All fully legal and theres loads of guys doing that. If your employer happens to be listed outside the UK then you probably wouldnt get taxed and source, so when you file the tax return it basically just confirms that your due no tax, this also means you havent paid any NI. If the employer is in UK everything would be PAYE and although you get the tax back, the NI would still be taken.
The big accounting such as PWC KPMG etc are working with HMRC to benfit the rich. Those majors are a more lucrative than HMRC so as an accountant you want to work with them. So thats where all the best talent ends up, which means that the majors put staff on secondment to HMRC which is welcomed by the staff at HMRC as its cheap labour for them, plus the staff will want to brown nose and hopefully get a job with a major. However while inside the HMRC those majors are helping dictate the direction of tax law and in some cases write some of it with little obscure loop holes specifically designed for the majors to take advantage of. Thats how we and up with a mess like the Irish/Dutch sandwich deal where all the tech firms avoid paying any tax within europe. The man in the street knows its not right, but with amazon etc giving little donations to political parties, noting will ever get done about it. Just look at all the directorships various cabinet members have, those MPs are basically being paid massive payments to pass on news from the working of government before anything gets announced. Pretty much every FTSE100 firm will have a director in either parliment or house of lords.
