I have experience as a tax payer in Estonia (employee only) and Australia (employee and business owner). In Estonia I login to my bank with my citizens ID card, click through a few screens ... and my tax return is done. All the financial information supplied by my employer to the government is immediately visible and checkable, not to mention donations made to tax-deductable organisations is also immediately visible. It is incredibly quick and convenient. In Australia it's just easier to leave everything to my accountant as they already have my quarterly business returns information; cost is still pretty reasonable (500AUD or so for the yearly business returns and the personal returns for my wife and I). But ... yeah ... in Estonia it just rocks. The ID-card based functionality for banking, digital signatures, tax ... just awesome.
It is similar in Norway - though I've only watched my spouse do his.
You get an email notifying you, log into the government website to check it. If you agree, the only action necessary is to pay the bill, if there is one. Otherwise, your refund will arrive. You have the option of doing actual filing or disputing the figures, but obviously don't have to.
Edit: The tax is figured out when you start work or update for things like marriage or children. This seems to include a trip to the tax authority for a personalized tax schedule.
In the Netherlands it is similar, most information is combined for you by the government, they even introduced an app to file your taxes last year. It probably is still a lot of work for businesses though...
We often hear about the advanced digital government in Estonia, must be nice to have such an open minded country.
