Define what counts as a referral
Start by agreeing what counts as a referral. Is it a warm introduction, a booked consult, or only a signed engagement letter? Most law firms tie credit to a signed engagement because it aligns incentives — the referring attorney is motivated to send genuinely qualified matters, not just names. Under ABA Model Rule 1.5(e), any fee-share between firms also needs the client's informed written consent and a division proportional to the work performed (or joint responsibility for the representation), so document those terms up front alongside the attribution rules.
Write down the attribution window too: how long after the introduction does the engagement need to start for the referral to count? Thirty to ninety days is common.
Agree how you'll work together
Decide how the relationship works in practice — who introduces whom, how opportunities are shared, and how you'll keep each other updated. Any terms of an engagement are arranged directly between the members involved.
Whatever you choose, keep it transparent. An arrangement both sides understand at a glance is one both sides will keep honouring.
Set clear expectations
Specify how and when you'll follow up on an introduction, and who is responsible for keeping the other in the loop.
Clear expectations are what turn a one-off referral into an ongoing partnership.
Cover the edge cases
Briefly address what happens if an opportunity falls through, gets reassigned, or doesn't fit after all. A single sentence prevents most disagreements before they start.