One of the changes made in the change to "Simper Super" went relatively unnoticed until now. All the media attention was around Retirement account withdrawals being tax free for retirees over 60 under the new rules, and the last minute opportunity to contribute up to $1 million into super before the new contribution limits come into effect on 1 July. It's only now that people have started to realise that under the new rules you will be hit with a 46% contribution tax rather than the usual 15% tax on pre-tax contributions if you haven't given your TFN details to your super fund manager. You also won't be able to make any undeducted contributions into a super fund after 1 July if you haven't given them your TFN - which would mean you can't get the co-contribution.
The media seems to have bought the government line that this change is all to do with making it easier to find the owners of "lost" super accounts. I think it has a lot more to do with clamping down on tax avoidance - the fact is that there have been a lot more tax file numbers issued to individuals than really exist in Australia. In the early days it was possible to open bank accounts under false names (no 100 point worth of ID was required back in the early 80s), and it was also fairly easy for someone to get multiple TFNs when they were first introduced (often by using a copy of a birth certificate obtained for a deceased person). These extra TFNs (under false names) were used to avoid tax. I'm sure there are still quite a few people working multiple jobs and using a different TFN for each, thereby getting the benefit of multiple tax free thresholds and low marginal tax rates. Up to now each of these jobs would have paid compulsory SGL amounts into a super account under those same false names. If the TFNs are provided for these super accounts the data matching used to find "lost" super accounts could help identify where one person appears to have multiple TFNs in use. If a TFN isn't provided for an account it could be a trigger for the ATO to check if the account appears to be legit. At the very least the lack of a TFN would mean any future contributions into the account would attract the top marginal tax rate.
I'm amazed that anyone in the media has swallowed the line that the requirement for TFNs will be used to reunite "lost" super accounts with their owner. After all, if the owner knows about the account and provides the TFN, it can't be "lost".