It’s one of the oldest tricks in the book but people fall for it all the time. Due to fact that domain ownership details are often public, unscrupulous companies are able to legally ‘jump the gun’ and send out invoices to to domain owners a few weeks or months before the legitimate invoice issues, usually for 10, 20 or more times the going rate. There is nothing illegal about this because the invoices state that they are offers, not invoices, but they also use alarming language like “Important: You will loose your domain” etc. An example is above, which I received a few weeks ago.
So to protect yourself it’s fairly simple — Know who you’ve got your billing with and contact them first if you receive any suspicious correspondence. Better still get to know this type of correspondence so you can recognise it yourself, it’s fairly obvious when you study it a bit. In short the only person contacting you regarding your domain should be your domain provider – this is normally a web developer, or it might be your hosting company. In the case of dot.ie domains the overseeing body IEDR may be in touch depending on how you registered your domain, and in the case of dot.com dot.net etc the overseeing body is ICANN and the provider sends out a contact details checker on their behalf email yearly.