Trust received cash refund after termination

My client closed a trust and filed the final tax return in 2016.

In Dec 2017 they received an unexpected cash refund for a deposit the trust made years ago and a 1099 for some interest income. Question -- Now that the trust is closed how do we treat the income and cash distribution to the beneficiaries? Looking for the easiest solution as the amounts are small.

Perhaps send a letter to the beneficiaries that says that the trust received cash, some of which is taxable. Please sign and date the enclosed statement promising to report your share of the taxable income, which is xxxx. Upon receipt of that document, I will send you your share of the cash, which is YYYY. Please do be sure to report the income because when the IRS contacts us for a trust tax return, I will be sending them copies of your signed statement along with an explanation that the trust had already terminated before the cash was received. Sincerely,

Thanks for your response.

It appears that the trust also received a 1099-Misc for a small amount of non employee compensation. Would it make sense for the trust to issue 1099's to the beneficiaries for their pro-rata amounts or would a letter to each beneficiary explaining that they should report their share of the income suffice?