If someone owes 230k on a mortgage and I can only offer 150k for the home, will the bank allow this sale? Is there a complication or does the owner just have to keep paying on the 80k difference?
The scenario you’re describing is called a short sale. The bank/lender must approve it. The bank/lender would have to choose to take a loss b/c it’s hard to have the owner keep paying the $80k difference when there’s no house the bank can threaten to take away.
There’s more info on short sales here, so now that you know the words you can look around. 
Also be sure to inform the homeowner if they do go for the shortsale that they will have to pay taxes on the difference between the sale price and what is owed so in this instance they would have to pay tax on $80k
Eric Medemar
In regards to your short sale answers. Just because you are offering 80k less than what is owed on the note does not mean that the bank will be willing to short the note. First the property needs to be in default and second the property must be over leveraged. Offering 150k to the bank when it is worth 230k will not fly. What is the property worth and how much work does it need.
Most lenders will not below 80% market value, and this with a good SS package.
Also, as far as the 80k. The seller would have to pay taxes on that only if you did not get the lender to waive the deficiency judgement.
You are asking a lot from this bank. What kind of condition is this property in?