In an article about the problems of pension lump sums and incorrect taxation, I saw details of last-minute filers. I don't know if they held back to the last minute on purpose. I'm not convinced there is any benefit, but you can't always be sure.
Yesterday hundreds of thousands of taxpayers attempted to file their returns at the last minute as HMRC struggled to cope with demand for their phone lines and online chat function. The Government said yesterday lunchtime that 1.1 million had left their online returns to the last minute and were expected to file before the deadline at midnight. More than 10.2m had already filed returns in paper or online.