Many years ago, when I first became an eikaiwa instructor at NOVA, I received a wooden stamp with デレック (derekku) written on it. I was told that this would be necessary for any major paperwork in Japan, e.g., registration at local city hall or ward office, opening a bank account and applying for most jobs. Even though デレック was not how I wrote my name in Japanese, I took special care of this stamp and used it many times over the years.
Up until this point, I never had any problems using my stamp. While most countries use a signature, Japan strongly believes in registered stamps. Japan even forced Korea to adopt this system while Korea was under Japanese rule, though South Korea officially dropped this system, believing it to be inefficient and easily susceptible to fraud. Japan, known for its reluctance to change, continues to use this system. Thank Japanese bureaucracy. While stamps are just another of Japan’s prehistoric practices, they are still pretty cool. Unfortunately, my stamp sucks. It would definitely be cooler to have a stamp in kanji.
After doing some research and consulting with the workers at city hall, I discovered stamps don’t have to be registered. The only time Japanese register them is before major purchases like a car or house. Because for these purchases, a registered stamp is necessary. This means for the majority of stamping duties, you can pretty much use whatever you want, even an 当て字 stamp of your name.