NVFAQ: Not Very Frequently Asked Questions about my last name:
1. Why did you change your last name spelling from “Chou” to “Jhou”?
I wanted to make my name's spelling look more like its pronunciation (which is
like “Joe”).
(This character is my family's name. It sounds roughly like “Joe”).
2. If your name is pronounced “Joe”, why was it spelled “Chou” in the first place?
Because the 19th century British diplomat Thomas Wade made it that way. He actually did have logical reasons for using the letters “Ch” to represent a sound like “J”, but you have to be a linguist to appreciate them (in a nutshell, "Ch" and "J" are both affricate palato-alveolar consonants). Wade's system was hard for laypersons to use correctly, and it was replaced after World War II by the pinyin standard. Anyone who left China before the change (like my parents) got stuck with the old spelling.
3. Why have I never seen the name “Jhou” before?
This spelling variation was recently devised in Taiwan, an island of 20 million people. On the Chinese mainland, where the population is 1.3 billion, “Chou” was instead replaced with “Zhou”. So you're much more likely to have seen that spelling variant. Of course, the original Chinese character is the same regardless - the only difference is how it's translated.
For more gory details about spelling Chinese names, see the following Wikipedia articles:
Pinyin romanization International standard adopted after World War II
Tongyong pinyin Variation of the above, used mainly in Taiwan.