When you co-invest, the lead sets the terms and you take them or pass. Decide fast, wire on time, keep the deck and updates confidential, never renegotiate behind the lead's back, credit whoever brought you in, and tell the founder and lead early what you plan to do in the next round. Reliability is the whole reputation.
Most angel checks are not solo deals. You join a round someone else is leading, sit on a cap table with other angels, or invest through a syndicate. None of the documents tell you how to behave in that setting, but founders and other investors notice, and they remember. The angels who keep getting invited into good rounds are usually the ones who are easy to have around.
What are the unwritten rules with the lead investor?
The lead does the work: negotiates the price and terms, often does the deepest diligence, and in a syndicate handles the paperwork. Co-investors get the benefit of all of that, which comes with a few obligations.
Take the terms or pass. The lead and the founder have agreed a price, a valuation cap or a discount. Asking for a better deal for yourself after that undercuts both of them. If the terms don't work for you, decline politely.
Don't go around the lead. Contacting the founder to renegotiate, or to get a side arrangement other investors won't see, is the fastest way to stop getting invited. If you need something, such as a pro rata side letter, ask openly and expect it to be offered to similar investors too.
Answer quickly. A soft yes that turns into silence costs the founder time and the lead credibility. Give a clear yes or no by the deadline, and if you need more information, say exactly what.
Wire when you said you would. A round that can't close because commitments don't arrive is a real problem for a company with limited runway. Treat a commitment as a commitment.
Ask before sharing. Decks, data rooms and the deal itself are shared with you in confidence. Forwarding them to a friend, or using them to bring in other investors, needs the lead's and founder's permission first.
The guide to negotiating a term sheet as an angel covers which terms an angel can reasonably raise, and when.
How should you treat the other angels in the round?
Other angels are future co-investors, and often future sources of deals.
Don't duplicate diligence. If ten angels each ask the founder for a different spreadsheet, the founder loses a week. Ask the lead what has already been covered, and share your own findings with the group if the lead agrees.
Don't push others out to make room for you. Asking a founder to cut someone else's allocation so yours can grow is noticed, and it rarely ends well.
Disclose conflicts. If you have invested in a competitor, or you are considering one, tell the lead and the founder before you join. They may still want you, but they should decide knowing it.
Keep disagreements private. If you think the round is overpriced or the plan is wrong, say so to the lead or the founder directly, not in public or in a group chat with other investors.
How do you handle credit and announcements?
Attribution creates more friction than most angels expect.
Credit the person who brought you in. A short thank-you, and returning the favor with a good deal of your own later, is how deal-sharing relationships last.
Describe your role accurately. "Participated in" is not "led". Claiming a lead role you didn't have, or implying you sourced a company someone else found, damages trust quickly.
Let the founder announce. Don't post about an investment before the company announces its round, and follow the founder's lead on what is public. Some founders keep rounds quiet for good reasons.
What happens at the next round?
Follow-on behavior is where co-investment relationships are tested.
Signal your intentions early. If you have pro rata rights, tell the founder and the lead whether you expect to use them well before the next round. A last-minute surprise in either direction complicates allocations. The explainer on whether pro rata rights matter to angels covers when those rights are worth exercising.
Don't use rights as leverage. Pro rata and information rights exist to protect you, not to slow down a round or extract a better deal for yourself.
Act as a group in hard moments. Bridge rounds, down rounds and recapitalizations go better when existing investors talk to each other before talking to the founder. A coordinated answer, even a no, is easier for a founder than ten different conditions.
Respect most-favored-nation terms. Some SAFEs, including one version of the standard Y Combinator SAFE, include a most-favored-nation clause that lets earlier holders take better terms given to later SAFE investors. If you invest later on better terms, expect earlier investors to receive them too.
What changes in a syndicate or SPV?
Investing through a syndicate adds one more layer of etiquette.
The syndicate lead owns the relationship. Unless the lead introduces you, contact the founder through them, not directly.
Don't front-run the syndicate. Seeing a deal in a syndicate and then approaching the founder to invest directly on the same or better terms, without the lead's carry, is widely treated as bad form.
Understand the economics before committing. Syndicate leads typically take carried interest and some charge fees. If those don't work for you, pass rather than complain after closing.
Keep syndicate memos confidential. Memos and updates are written for members. Sharing them outside the syndicate breaks the trust the lead relies on.
The guide to syndication explains how syndicates are structured, and the walkthrough on joining an angel group or syndicate covers getting in. More on deal terms and portfolio building is in the angel investing section.
Frequently Asked Questions
Q:Can I negotiate different terms from the lead investor?
Usually not, and asking is often seen as poor form once terms are agreed. Side letters for things like pro rata rights or information rights are common, but expect the founder to offer the same to similar investors. If the main terms don't work for you, it is better to pass.
Q:Is it okay to share a deal with friends?
Only with the founder's and lead's permission. Many founders welcome introductions to helpful investors, but they want to know who is seeing their materials. Ask first, then make a warm introduction rather than forwarding the deck.
Q:What should I do if I can no longer fund a commitment?
Tell the lead and the founder immediately, before the closing date. The earlier they know, the easier it is to fill the gap. Disappearing is far more damaging than an honest withdrawal.
Q:Do I have to follow on in later rounds?
No. Following on is your choice, but tell the founder and the lead your intention early, especially if you hold pro rata rights. A clear no lets them plan the round.
Q:How do angels get credited for bringing in a deal?
Mostly informally, through thanks and reciprocity. In a syndicate, the lead's carried interest is the formal reward for sourcing and running the deal. Outside syndicates, sharing good deals back is how credit is repaid.