I wish that the IRA custodian would file the Form 990-T. Quite often they rely on the IRA owner. Normally Form 990-T is due May 15 for a calendar year entity, but IRA UBIT must be reported by April 15 (a very busy deadline).
The other bad news about UBIT in an IRA is that there is no reliance on the prior year if you owe tax for the first time. Once income is over $1,000 and tax is due you get an underpayment penalty if no Form 990-T was required the previous year.
For a final insult to injury item with UBIT and IRAs, the tax is supposed to be deposited with a Federal coupon at the bank. An IRA is treated as a corporation for tax payments and underpayment purposes; that's what causes these nasty quirks.
If anyone is thinking of investing in a partnership in the IRA, Please Do Not.