Is it common for a listing to include a tail period after it ends?

Yes, tail (or holdover) clauses are a standard feature of most business-sale listing agreements, not an unusual add-on to be suspicious of. The purpose is straightforward: without one, a seller could simply wait out the listing term and then close directly with a buyer the broker already found and introduced, avoiding commission on work the broker actually did. A tail clause extends the broker's right to commission for a defined period after the listing ends, but generally only for buyers they can show they actually introduced during the term.

What varies from agreement to agreement is the tail's length and exactly how "introduced by the broker" is defined — some agreements require the broker to provide a list of prospects at the point the listing ends, which then defines who the tail clause covers; others are written more broadly. Since this is standard, the useful question isn't whether a tail clause exists, but what it actually says, and whether it's reasonable in scope and length compared to the rest of the agreement. A Treadstone business lawyer reviewing your listing agreement should always flag this clause specifically.