IRA did not withhold tax

If they don't have withholding they should make estimated tax payments.

Too late for 2022.

You don't really "file" 1040ES, anyway.You just need to pay, and you can follow safe harbor rules.

The whole point is to be Prepaid in your taxes, and there are a number of ways to compare these prepayments to determine if the taxpayer might be underpaid and subject to an underpayment penalty.The prepayments can be from W2 withholdings, distribution withholdings, estimated payments, and from any combination of these.

For instance, when there is a windfall event, they can pay an Estimate. They don't have to wait for a scheduled due date. Unfortunately, they have missed the final date of being on time for 2022.

They doesn't mean there will be a penalty, because that is not what determines underpayment.

The IRS will not charge you an underpayment penalty if:

• You pay at least 90% of the tax you owe for the current year, or 100% of the tax you owed for the previous tax year, or
• You owe less than $1,000 in tax after subtracting withholdings and credits

This rule is altered slightly for high-income taxpayers. If the Adjusted Gross Income (AGI) on your previous year’s return is over $150,000 (over $75,000 if you are married filing separately), you must pay the lower of 90% of the tax shown on the current year’s return or 110% of the tax shown on the return for the previous year.

They also can try the annualization method for reporting the income against any payments made, and the IRS can waive penalties, as well.

Your state will also have estimated tax payment rules that may differ from the federal rules.

Have you determined they have not met any safe harbor at all?