Hi online community, need your advice here: 

I have a potential new client whose previous preparer retired. After talking to him, he told me that he owns an apartment in Mallorca, Spain  and it has been rented for the past 10 years but has never included that in his income taxes. To tell you the truth, I have never had a case like that before, but after reading some Google searches it seems that foreign rental income should be included in Schedule E, almost with the same laws that a US rental income. What would you do on this case? Had anybody have cases like that before? I will appreciate your comments. Thank you everybody.