The settlement sheet (HUD-1) 100 series numbers page 1 adds up what your charges are to buy the house:
- sales price
- closing costs from page 2
- pro rations per the sales agreement.
Below that, the HUD-1 200 series adds up your credits to buy the house:
- Your mortgage
- Deposit(s) you already paid the seller
- Seller credits
- Lender credits
Below that your HUD1 page 1 subtracts your credits from your charges and the difference is what you owe!
Unless the seller paid ALL of the closing costs (they are limited to 2-6% seller credit so this may not be possible if you have very high property taxes for example) you will owe more than your down payment, you will also all the closing costs that the seller did not pay.
What you owe at closing should be fairly close to what your loan officer showed you in writing several times (signed 1003 application page 3, fee worksheet).