The umbrella: when an agent says a home is "under contract," they mean a purchase agreement has been signed by both parties and earnest money (typically 1-3%) is deposited — covering both the contingent phase (conditions unresolved) and the pending phase (conditions cleared). The label tells you a contract exists; it does not tell you how fragile it is. That requires the contingency map.

What is legally true while under contract:
• The seller is contractually bound to THIS buyer — they cannot sign a second primary contract or simply take a higher offer that arrives later (doing so is breach, with real damages exposure)
• The seller CAN accept written backup offers, ranked in order, that activate only if the primary contract terminates
• The buyer's exit rights are defined entirely by their contingencies — inside them, exits are clean; outside them, the earnest money is at stake
• The listing usually remains visible on portals (MLS rules require status accuracy, not removal) — which is why "if it's under contract, why is it still online?" is the most-asked question in real estate search. Answer: because the industry knows roughly 5% of these contracts die.

Yes, you can offer — and here is the clean way to do it:

1. Intelligence first. Your agent calls the listing agent: which phase (contingent or pending)? Which contingencies remain, with what deadlines? Is the seller accepting backups? This call is routine and answered honestly nearly every time — listing agents WANT backup interest as leverage over their current buyer.

2. Submit a written backup offer with a backup addendum. The addendum is the key document: it places you in a numbered position (insist on knowing your rank), specifies that your offer activates automatically upon termination of the primary contract, typically delays your earnest money deposit until activation, and — critically — preserves your right to withdraw in writing at any time before activation. You are first in line AND free to keep shopping. There is no trap.

3. Do not bid against yourself. A backup offer does not need to beat the current contract price — it needs to be attractive enough that the seller declines to renegotiate with a wobbling primary buyer. Sellers with strong backups stop giving inspection credits.

4. Set the back-on-market alert regardless. A failed contract creates the most certainty-hungry seller in the market, and the first credible buyer through the door inherits all the leverage.

The etiquette note: approach through agents, never by knocking on the door of a seller in contract — interference with an existing contract is both bad form and, done aggressively, a genuine legal exposure called tortious interference.

For sellers, the under-contract period is not passive waiting — it is risk management:

• Accept and rank backup offers. A signed backup converts your negotiating posture overnight: when the primary buyer's inspector produces a $9,000 repair request, a seller with no backup negotiates; a seller with a strong backup says no. Listing agents should be soliciting backups on every contingent deal — ask yours if they are.
• Keep showing (CCS status) during fragile contingencies — especially home-sale contingencies, where pairing with a kick-out clause (24-72 hour bump rights) keeps your options alive.
• Police the deadlines. Contingency periods expire by date. A buyer who hasn't completed their inspection by day 12 of 15, or whose loan commitment letter is overdue, should be receiving formal notice from your agent — silence extends fragile deals.
• If the contract dies, relist fast and frame it. "Buyer financing fell through — home inspected clean, report available" is a relisting that protects your price. An unexplained back-on-market flag invites every buyer to assume the inspection found a body in the crawlspace.