If you already had a Schedule B on the original return, you’ll want to include everything that was on it, plus the new income. (In other words, submit a complete, updated Schedule B.)
Also, if the Schedule ends up so crowded that your info about the foreign payer doesn’t fit, including the additional statement would be great. I’m guessing that’s why Mary (above) recommended the statement and not the Schedule B, anyway. (Foreign circumstances don’t always fit neatly into the usual tax reporting requirements, so a little flexibility is required. And again, the IRS isn't likely to be concerned as long as things are clear and you’re obviously making a good-faith effort to comply with the tax rules…)
You're welcome, @cathiexu!
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