Also, Risk. If you are an employee and you unintentionally screw something up then you may get fired. As a contractor, if you type a command in the wrong ssh

Also, Risk. If you are an employee and you unintentionally screw something up then you may get fired. As a contractor, if you type a command in the wrong ssh session and take down the production system you may get sued, at which point it really matters if you are working through a limited liability company or you are personally invoicing them. You have to price in the risk. A UK limited company involves a significant amount of paperwork and administration. You can do it yourself or pay an accountant thousands a year. There is monthly and yearly paperwork. There is the pain of the "making tax digital" plan to make companies submit accounts only electronically using accounting software. A thing that sometimes costs people a pile of money is that VAT is on a rolling year. You can be under the VAT limit in your tax years, but if you invoice over 85K at the end of one tax year and the start of another then they can say "Gotcha! you must pay us 20% of your invoices and a big fine right now!" There is also IR35. There is some risk of the government saying that you are a disguised employee and demanding a load of extra tax. It depends on things like does the contract say that your company can send anyone to do the work or does it have to be you.