What Is COB? Sorority Continuous Open Bidding Explained

Updated 7/8/2026

COB stands for Continuous Open Bidding, and it's how sorority chapters that aren't at campus total fill their remaining spots outside of formal recruitment. Here's what it is, how it works, who it's for, and why it exists.

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A Quick Note on Grammar

We use COB a few different (and grammatically incorrect) ways in this post, and that's how it's used in real life:

Noun: "She got a bid through COB."
Adjective: "She's part of the COB class this semester."
Verb: "She decided to COB after her suicide bid didn't work out."

Don't let it throw you.

Formal recruitment ends, Bid Day happens, and for most PNMs, that's the whole story. But not every chapter fills up during that window, and not every student who wants to join a sorority goes through formal recruitment to do it. If you're new to recruitment, here's how formal recruitment works.

What COB Is

COB is short for Continuous Open Bidding, also called Informal Recruitment. It's how chapters that aren't at campus total extend bids outside of the formal recruitment process.

During recruitment, each chapter has a quota, the number of new members they're allowed to accept that cycle, set by the campus Panhellenic based on how many Potential New Members (PNMs) sign MRABAs. But quota only caps that particular recruitment cycle. Campus total is the chapter's overall size limit, not just new members, and it is reset by Panhellenic each semester. A chapter can fill its quota during formal recruitment and still sit below campus total, and COB exists to close that gap. For a full breakdown, here's everything you need to know about quota and campus total.

In formal recruitment, every chapter hosts the same number of parties, registered PNMs must visit every sorority to start, and there are strict guidelines for how invitations are extended and what's allowed at those parties. In contrast, chapters can choose to hold COB-specific events or they can just invite a student they like for coffee dates or to a sorority event. There are no set number of meetings and chapters can offer a bid anytime.

COB is a standard, ongoing part of how a chapter manages its size. Many chapters have a Director of COB on their executive board, who reports to the VP of Membership Recruitment.

It isn't run or coordinated by the College Panhellenic, chapters aren't required to participate, and there's no separate registration process for a student to take part.

Why a Chapter Might Not Be at Total

Why a chapter ends up below total: a large graduating class that year, a chapter that started recruitment already below total, members dropping out, or a new member who drops before initiation. Missing quota at formal recruitment is another reason a chapter has room left to fill, but a chapter running COB isn't necessarily a chapter that's struggling with numbers.

When COB Happens

COB opens after the formal recruitment cycle ends, after Bid Day. Some campuses set a moratorium between Bid Day and COB, typically a week or two, that gives new or rebuilding chapters a head start in contacting unmatched PNMs before COB opens up for other chapters. COB can technically run any time formal recruitment isn't in session, though in practice it usually happens in the same semester as formal recruitment, as early as possible, so members who accept bids via COB can join the newest member class without falling too far behind and potentially be initiated at the same time, or it runs independently from that class and happens at the start of the next semester.

Who's Eligible

Any unaffiliated, eligible student can take part in COB.

Students who never went through formal recruitment. Maybe they never registered because they weren't interested in the idea of sorority until they got to campus, or they missed the deadline. Maybe the fully structured multi-round process felt like too much, or they had a scheduling conflict. COB gives them a way in before the next year's formal recruitment period.

I Never Thought I'd Join a Sorority

Before I got to school, I didn't think sororities were for someone like me and it didn't even occur to me to register for recruitment. I had seen TikToks that looked like a sea of blonde girls wearing the same outfits, doing dances in front of giant houses, and the whole thing just turned me off. I'm more emo and don't look like Elle Woods. But then I got to campus and my roommate joined DG. She was cool and seemed like she was doing a lot more things on campus than I was, which made me more interested. In October, she invited me to dinner at the house and it was really warm and fun. I sat between one member who worked in a neuroscience lab, which is something I wanted to do, and a queer member with spiky black hair who I never would have guessed was in a sorority. They invited me out for coffee the next week and then to a semiformal, and I met a bunch of members who seemed like my kind of people. Ultimately, they offered me a bid in January and I accepted. I'm so glad I was paired with a roommate who rushed and exposed me to what sorority really is, not just what they show on social media. I'm a sophomore living in the house now and I cannot imagine my life without DG. I'm on our softball team, my big sister is amazing, and I love when I see someone wear letters on campus and know she's someone I can go sit with without thinking twice. I am grateful I could COB and didn't have to wait until now to join. —Kayla

Students who dropped out partway through the process. Formal recruitment moves fast and the process can be emotionally taxing. Sometimes a PNM steps away from it but still wants to be part of Greek life. COB gives them another shot.

Students who did a suicide bid and didn't match. If a PNM only lists one chapter on her MRABA and doesn't get a bid, she's eligible for COB. This option is a great plan B, but there's also no guarantee with COB. Her target chapter may not have room to extend more bids after recruitment, and even if they are, she might not receive a bid. For the full picture, here's everything you need to know about suicide bids.

My Suicide Bid Didn't Work Out, but COB Did

I loved sorority recruitment, until I didn't. Everyone, including me, assumed I'd join a sorority when I started college, and I loved meeting all of the girls and seeing all of the houses. I was invited back almost everywhere and preffed at two chapters I could see myself in. But at pref, AXO made me feel so much like a part of them already, and APhi was ok, but I just didn't feel the same connection. I was paired with a member I hadn't met before and we didn't really click. When it came time to fill out my MRABA, my Rho Chi advised me to rank both houses, but I just knew AXO was for me and didn't think I'd ever feel at home at APhi, so I did a suicide bid. I was devastated when my Rho Chi called the next morning and told me not to come to Bid Day. It was awful. I just wanted to go home. I was on the phone with my mom for at least an hour. Fast forward to the Monday after Bid Day when I got a DM from the member who preffed me at APhi. She invited me for coffee with her and her big. She said she had really liked me at pref and was disappointed that she didn't see me at Bid Day, and hoped I'd consider APhi now. I didn't know what COB was and I didn't want to do it, but my mom made me, and I'm so glad she did. Our coffee date was really fun and I actually connected more with her big than with her, but I loved seeing how they got along even though they were really different. I knew I wanted to be in a sorority and didn't want to miss this chance, so I said yes to APhi right there. It was so fast and the member class was so big that most people didn't even realize I wasn't at Bid Day. I was initiated with that member class and APhi has been my home ever since. My advice is to not be afraid of COB. But I don't know that I can advise anyone to suicide bid. I took a big chance. —Maddie

Students who were dropped from formal recruitment. It happens. Not every PNM shines during recruitment because it can favor extroverts, strong conversationalists, and students with experience presenting themselves. Students who have other strengths might not make a strong enough impression to be invited back even though they want to join and have a lot to offer. COB's slower pace and lowkey events may offer a better avenue for those PNMs.

The COB New Member Experience

Since COB isn't centrally coordinated, the experience varies a lot. On the low key end, a chapter member might reach out directly to a student they've met on campus or a PNM they met during recruitment and invite them for a casual meetup like coffee or a walk. It might take one meeting for a chapter to decide to extend a bid, or three or four. Both the chapter and the student need to feel comfortable, so it's ok for the PNM to ask to meet more members or attend an event if they haven't been to any.

In some cases, the chapter's Director of COB or VPMR will reach out to almost every PNM who registered for recruitment but didn't accept a bid to see if they're interested. They might still invite them for casual 1:1 meetups, or on the more structured end, some chapters host small events for students interested in COB. Those events are designed to recruit but don't follow the strict time limits and guidelines that are applied in formal recruitment, and chapters aren't coordinating bumping the way they would during formal recruitment rounds.

An interested student can explore informal recruiting with multiple chapters, and the only timelines are imposed by the chapters. One might extend all of their possible bids on the same day and expect the student to have made a decision by then, and others might do one-offs. In any case, it's a good idea for the student to ask each chapter what their COB process is so they're not left wondering about next steps. (That's one nice thing about formal recruitment: a PNM knows where she stands after each round.) As with formal recruitment, a PNM can only accept one COB bid.

Once a new member is invited to and agrees to join through COB, she'll need to sign an MRABA (this version doesn't have ranking). The new member experience varies from there: sometimes the new member joins early enough to join the most recent new member class, sometimes there's a class of COBs that goes through new member education and initiation together, and sometimes there's just the one COB at a time who gets a personalized new member experience. New COB members will get big sisters and be initiated just like any other member.

FAQ

Is COB the same as a snap bid?
No. Snap bidding happens at the very end of formal recruitment, before Bid Day, and is specifically about reaching quota. COB happens outside of formal recruitment, runs independently of the school's Panhellenic, and doesn't have to be about quota. It's about reaching campus total.

Can you be interested in or visit more than one chapter during COB?
Yes. You can talk to and consider more than one chapter during COB. You can only accept one bid.

Does having COB mean a chapter is a bottom house?
No. A chapter using COB is filling spots based on campus total, which is independent of perceived ranking or popularity. If five members graduate early, a chapter might extend bids to keep their numbers up. It's also possible that a chapter that doesn't reach quota during formal recruitment will run COB, but that doesn't mean they're struggling for members. The numbers sometimes just work out that way. And for what it's worth, the whole idea of "top house" and "bottom house" is outdated. Every sorority offers sisterhood, leadership and growth opportunities, and a place to call home. The point is to find the chapter where you'll thrive, no matter what you see on GreekRank or YikYak.

Are COB dues different from standard new member dues?
Sorority dues are a mix of national organization dues and local chapter dues. National fees, including one-time new member costs, are the same for all new members. Chapter dues may be prorated to account for a new member's start date.

If I COB, will I still have a Bid Day?
It depends on the chapter. If a chapter has more than one or two COBs at the same time, they're likely to have a Bid Day celebration of some kind, though realistically it's not going to be the same scale you see on social media. There are fewer chapters involved and they're not likely to be on the same timetable. Some chapters have larger COB classes and do bigger events; if Bid Day hoopla is important to you, ask before you accept your bid.

COB isn't a consolation prize. It's the process by which chapters that aren't at campus total reach it, and it opens the door to students who, for all kinds of reasons, find their way to a chapter outside of formal recruitment. If you're weighing whether it's the right path for you, know that it leads to the same place: lifetime membership in an organization that supports you and your goals.