In most short sales, the seller doesn't pay closing costs out of pocket. The proceeds from the sale typically cover real estate commissions, title fees, and other standard closing costs, and your lender approves that payout as part of the short sale agreement.
What you won't get back is profit. The whole point of a short sale is that the home sells for less than what's owed, so there's no equity left over for you at closing.
Washington adds one wrinkle worth knowing. Because deficiency judgments are barred after a non-judicial foreclosure here, but not automatically barred after a short sale, some lenders try to recoup costs by holding the seller responsible for fees a foreclosure would have absorbed differently. This is negotiable. It's one of the items your team pushes back on during the approval process, not something you're expected to simply accept.
If there's a second mortgage, HOA lien, or judgment lien on the property, those creditors also have to agree to release their claims for the sale to close. Each one may ask for a small payout in exchange for releasing the lien. This is normal and is built into the negotiation, not an extra bill that lands on you afterward.
Every situation is different depending on your loan balance, your liens, and your lender. We will walk through your specific numbers with you before you commit to anything.

