Maj is right, although she confined it to interviews.
In normal business dealings, you would normally answer 'your welcome' if you are the leading party, like in the example of Maj. If the interviewer said to you 'thank you for coming', you would respond by saying 'my pleasure', it would be a little presumptuous to say 'your welcome'.
However if you as the one being interview proactively said 'thank you for the invitation..' it would be appropriate for them to say 'your welcome'. Saying 'my pleasure' would also be acceptable.
This is more to do with etiquette, than correct grammar.
In an informal situation, an Australian would reply to 'thank you' with 'no worries mate'..... (thats for you Mike in Japan
Hope this helps.