§ 8148.  Insubstantial allocations not required.

    If a trustee determines that an allocation between principal and income required by section 8149 (relating to retirement benefits, individual retirement accounts, deferred compensation, annuities and similar payments), 8150 (relating to liquidating asset), 8151 (relating to minerals, water and other natural resources), 8152 (relating to timber) or 8155 (relating to asset-backed securities) is insubstantial, the trustee may allocate the entire amount to principal unless one of the circumstances described in section 8104(c) (relating to trustee's power to adjust) applies to the allocation.  This power may be exercised by a cotrustee in the circumstances described in section 8104(d) and may be released for the reasons and in the manner described in section 8104(e).  An allocation is presumed to be insubstantial if:

    (1) the amount of the allocation would increase or decrease net income in an accounting period, as determined before the allocation, by less than 5%; or

    (2) the value of the asset producing the receipt for which the allocation would be made is less than 5% of the total value of the trust's assets at the beginning of the accounting period.