No. Checks coming from friends, family or other sources that are not your own earned money or already saved funds cannot be used.
For example, if your best friend writes you a check to reimburse you for dinner the other night, you cannot count this money in your account that holds your down payment.
Checks you receive for insurance reimbursements, medical payment reimbursements, a lottery win, a refund from a store or creditor are acceptable sources for deposits because they represent items owed to you for something you either already paid or earned. A copy of the check and sometimes the payment voucher is necessary to document these types of funds. Always make a copy of any check(s) you deposit that are not payroll checks.
If you deposit a check from your savings account, or money market or retirement account to your checking account, this is ok. We would then have to look at all the deposits for the last 60 -90 days into your savings, money market or retirement to determine the source of the funds.
I would suggest you have a main account that receives your payroll deposits. Then I would transfer household money from that account to another checking account at another bank. The household account would not be used for down payment and you could deposit any type of funds into this account to pay your household bills, buy items for purchase, and any other items you need. If friends or family give you holiday or birthday gifts, they could be deposited into this account.
Your main account would then be free of unacceptable deposits and you could accumulate your down payment in an account with limited transactions that would need to be reviewed. The reason I suggest a different bank is that many banks consolidate all your accounts into one statement and this would allow the underwriter to look at the household account and again, see all the other types of deposits.
See “What other things does the lender look for on account statements?” to see what additional review you would avoid using the two account system.