What Does This Letter on a Door Mean

[Joe Splitrock]

I was driving around and noticed a property with a letter on the door that was not like other foreclosure letters I have seen. Typically the foreclosure letters say the property is vacant, but this letter just said to call a phone number with your account number to discuss payment. I am not familiar enough with the foreclosure process. Is this possibly a situation where they want to contact the owner prior to moving into foreclosure? It looks like a nice buying opportunity. Zillow says the property was purchased for $97K in 2013 and was listed for sale for $150K several months ago. Then the listing was removed. Not sure what happened here but seems like it could be a buying opportunity. Anyone have an idea of the best way to pursue this?