The instructions for Form SS-4 seem to make a trust ID# mandatory, as rhp pointed out. I'm guessing most clients of TPAs are like mine - you can get the number for them, tell them how and why to use it, and most will still register their plan investments under their EID#. Thankfully, in the majority of such instances the IRS doesn't catch this. However, once in a great while we do receive an IRS letter stating that 'Joe Client owes us a ton in back taxes, penalties, etc. because we've noticed he's never paid tax on any of the dividends, interest or capital gains on the investments in this corporate taxable account'. It usually gets straightened out without the client having to pay anything, but only after you've twice explained what the intention of the investments were to half of the IRS. Avoiding this potential frustration is another reason to get a trust ID# now. One more reason is that you may be the unfortunate one to get an IRS agent who won't let it slide as an "innocent clerical error" and demands payment. We haven't seen this happen yet, but you never know.
[This message has been edited by mming (edited 05-16-2000).]