More than 15,000 people have left the Lutheran Church in Norway in under a week after the launch of a new digital membership page on the Church's own website.
Using the page, Norwegians can check whether they are members or not, and also can with a few simple clicks leave if they think they have been signed up in error.
In the same way, they can easily join the Church.
The digital membership system was introduced to streamline the existing system which has been criticised.
It was anticipated that the number of departures would exceed new members, but the first few days alone led to 10,854 resignations. Over the week, 15,053 people left in total, nearly as many as the 15,900 who left in the whole of last year.
The number of departures is a small fraction of the total 3.8 million members, about 73 per cent of the country's population.
According to Norway's VG News, so far this year the Church has received 24,278 resignations and 1,369 enrollments.
Norwegian bishop Helga Haugland Byfuglien said she was not surprised.
"We were prepared for a significant number of resignations and have great respect for the individual's choice. We take these signals seriously. Our task will be to pass on the Christian message and to convey the important role the church can have in people's lives," she said in a statement.
Kristin Gunleiksrud Raaum, church council leader, said: "We will continue to have a broad and open national church. But no-one should be a member of a religious community against their will, and therefore I am glad that this self solution is in place. Those who mistakenly listed as a member of the Norwegian Church or who do not wish to be members can now easily change their status, and it will give us a more accurate registry."