Should I copyright my book before sending it to publishing companies?

From a publisher’s perspective, stealing content would be bad for business. It’s their job to pay you for your work if they like it. To steal it and have someone else write it would just be a tedious ordeal that nobody would put time or effort into doing. It makes no financial sense for the publishing company to operate that way. It simply doesn’t happen.

Copyright in Vietnam 

With that said, it does sound like you need some more information about how to copyright your book. It’s true that once you’ve written something and attached your name to it, then technically it has a copyright already. However, the difference is that without a formal copyright, you will have a harder time in the event that someone ever does plagiarize your work and try to sell it as their own.

Hope this helps!