Lenders generally get less in love with a file, as the need for exceptions, to their policies, increases.
Example #1
Let’s say you have a strong application (good income/credit/job history etc), with a down payment of 30% (from your own resources), but the lender in question will give you a better rate if you have 35% down payment. You have a family member offering to lend you the remaining 5% (of the purchase price) so you can get the lower rates.
Example #2
Let’s say you have no down payment, and have a family member willing to lend you 5% (of the purchase price), so you can have the needed minimum (with the lender in question). And, you just got out of bankruptcy last week.
As you probably guessed, example #2 almost-certainly requires more exceptions from the lender’s policies, making it less likely to be approved. But, that doesn’t mean it isn’t worth asking:
“You miss 100% of the shots you don’t take” – Wayne Gretzky