I wasn't sure where to post this, so I though I would try here first. I recently opened a new account at my bank. I then received a letter saying that the bank doesn't have on record my Tax File Number, or Australian Business Number. They didn't request it, but said that without it I may be taxed on any interest my accounts make. This might explain why my accounts in the past have not been receiving any interest. Anyway. I was just curious as to what they actually need this information for? Cheers. PS. This seems like an excellent forum.