If a seller offers to pay a buyer's agent fee through off-MLS negotiation, the buyer's agent must:

Rejecting the offer entirely is not required. Buyer's agents can accept compensation from sellers as long as it's properly disclosed and doesn't exceed the agreed amount. The key is transparency and adherence to the representation agreement, not automatic rejection of seller-offered compensation.

Accepting without telling the buyer violates the agent's fiduciary duty of disclosure. Buyer's agents must inform their clients of any compensation offers from sellers to maintain transparency and avoid conflicts of interest that could compromise their representation.

Reporting the seller to NAR is unnecessary and not a standard requirement. While seller-offered compensation through off-MLS negotiation may be unusual, it's not inherently reportable to the National Association of Realtors unless it violates specific ethical standards or laws.