In the UK the equivalent to IRS is called HMRC. People who are just in normal employment dont need to submit their taxes because it Pay As You Earn (PAYE) and

In the UK the equivalent to IRS is called HMRC. People who are just in normal employment dont need to submit their taxes because it Pay As You Earn (PAYE) and so its all obvious. But if you are self employed or get paid dividends or made a capital gain or sundry other exceptions then you have to submit a tax return. HMRC provide a web app for you to submit your tax return should you need to. Its a pretty good app. Its long and complicated because thats how taxes are, but its pretty good. There's also an API where 3rd parties can develop their own software for submitting your taxes. I guess you have to get some sort of approval to use it, but its there. There are a few doubly-exceptional cases that are not covered by the default HMRC web app. E.g. if youre in a partnership (a sortof type of ad-hoc company) and need to do a special sort of return. A bunch of other edge cases too. For those you go and search out a third party software supplier from an approved list. Or fill in a paper form. TDLR: something sane is possible