Hector, if I understand you correctly the deal is
- You take over loan with ~186K remaining balance (235K after 10 years of payment)
- You also pay a total of 25K down
- So the total you're buying it for is ~211K.
Is that consistent with what you think you're paying?
I do have a few questions.
Do you have some kind of proof that all payments have been made on time (so the remaining balance is actually 186K) or what the current payoff amount is?
(It's often on the monthly statement and you could also call the bank with the seller who'd probably need key in the loan #, birth date, last four of SSN, etc.)
Also you'll want to read the fine print (i.e., all pages) of the mortgage and promissory note. (The mortgage is recorded but the note usually isn't.) Specifically what you're looking for is any balloon payment (the whole amount being due at a certain date before the 30 years - uncommon for a regular mortgage but possible) and especially and adjustable rate language (usually covered in something like an "adjustable rate rider" toward the end).
If the mortgage includes escrows for taxes and insurance, I'm not sure the #s add up - I'd expect the payment to be a lot higher. A 235K 30 year mortgage at 4.2% would have a base (principal & interest) payment of 1150/month and I'd expect taxes and insurance to add at least several hundred more.
So I'd recommend looking closely at the last monthly mortgage statement, and last year's end-of-year mortgage payment summary where it would list all the 2015 escrows and payments.
Another point is that what you're proposing doesn't sound like "assuming" the mortgage - which is a separate process requiring lender approval, checking your credit, qualifying you for the loan, etc. - but buying the property "subject to" the existing mortgage without telling the lender. (Most mortgages these days aren't assumable anyway, so unless you know for a fact this one is, it probably isn't.)
Re: the "due on sale" clause, various real estate gurus have, over the years, proposed a variety of schemes to try to conceal the fact that the property has changed ownership from the lender, such as putting the property in a trust (which technically does violate the due on sale/transfer clause though it makes it harder for the lender to know).
Honestly, I'm not a big fan of those concealment strategies, and I don't think they're likely to work too well in today's digitized world.
One way a lender could easily tell if a property had transferred would be that usually the insurance policy changes, and mortgagees (lenders) get notified whenever an insurance policy changes. So unless you like paying double insurance (the seller's old policy which does not cover you, and your own policy that does) that's a tip-off right there.
Another is simply that when property ownership changes hands, trust me, it shows up in a thousand databases within a month of it happening.
If you buy something subject to, you're basically playing roulette hoping the lender will never call the loan due. Which they may not, for a long time. But I honestly think that if interest rates rise, lenders will start doing so in an effort to force homeowners to refinance at higher rates. That's not the end of the world if you can afford the higher payments, but it's also a tough pill to swallow - it's a big difference between deciding to refi on your terms, and being told you have 30-60 days to refi or you'll lose the property to foreclosure.
Also, you and/or the seller may not realize, s/he probably won't be able to buy another property as long as this mortgage (and its payments) are still on her/his credit report. So that could be an issue down the road.
I don't think a wrap mortgage is what's going on in this situation - that would be more if you in turn sold the property to someone else with seller financing and "wrapped" the underlying loan with a bigger loan, and then paid the underlying loan from the payments you received.
However with the various consumer protection laws that happened after the last real estate crash, you probably don't want to be selling a property with seller financing unless you know you're selling it to a non-owner-occupant.
I guess the most important question is, what makes this house/property a deal?
There's a lot of complexity in buying subject-to, and some not-insignificant risks. I wouldn't recommend it to a beginner at all. And with any complex/risky situation, the question is, what are you getting in return for taking on that risk? What's great about this particular house/deal that would make you want to do this rather than just saving up your own down payment over the next year and getting a regular mortgage and avoiding all this risk/complexity?