Earnest money is effectively a “good-faith deposit.” It’s like saying, “Here’s my Offer to Purchase and here’s some money to go along with it to let you know that I am serious.”
This is usually done within 3 days of having an Accepted Offer on a house. The amount is usually between $500 and $2000.
We generally recommend you use your Buyer’s Agent’s best advice for this, because they are the one who is actually negotiating the offer, and sometimes the amount of Earnest Money does matter. Sometimes it’s the difference between you getting the deal or not!