> For the complete documentation index, see [llms.txt](https://hackdays-guide.mlh.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hackdays-guide.mlh.com/help/frequently-asked-questions-faq.md). # Frequently Asked Questions and Contact Resolve Hack Day edge cases and contact the MLH team when your approval is unclear. Start with [Requirements and Eligibility](/start-here/requirements-and-eligibility.md) for the canonical program rules. This page covers common exceptions and edge cases. For general advice about organizing teams, sponsorship, marketing, venues, or full-scale hackathon operations, use the [MLH Hackathon Organizer Guide](https://guide.mlh.com/). For questions about a specific Hack Day approval, email . ## Format and Eligibility ### Can Registration or Check-in Happen Online? Registration, event communications, and administrative work may happen online. Check-in may not happen online or in advance: organizers must check in each attendee through OrganizerHQ while they are physically present at the venue. The rest of the event—including building, mentorship, demos, judging, and closing—must also take place entirely in person. ### What If I Want to Run Longer Than 12 Hours? A Hack Day must run for at least 3 hours and may not exceed 12 hours. Apply for [MLH Event Membership](https://mlh.link/member-event-application) if you are planning a longer hackathon. ### Can More Than 50 People Attend? Yes, if your venue and organizing team can safely support them. Reimbursement is capped at 50 verified OrganizerHQ check-ins even if more people attend. ### Who Can Participate? Hack Days can welcome professionals, students, and other community members unless the event approval or assigned partner specifies a narrower audience. Review the [partner eligibility matrix](/start-here/requirements-and-eligibility.md#partner-eligibility) before advertising an audience. ### Does the Event Need a Theme? No. You may choose a theme for your community and add local categories. Your approval or onboarding materials will identify the MLH partner category assigned to your event; share that category with attendees in advance and present it during the opening ceremony. ## Applications and Registration ### What If Registration Is Already Open Somewhere Else? [Submit a Hack Day application](/start-here/apply-to-host.md) and email . The MLH team will review the existing registration setup and tell you how to proceed. Do not assume an external registration page replaces OrganizerHQ. ### Can I Advertise a Preferred Partner While My Application Is Pending? No. A partner preference is not an assignment. Wait for approval before advertising MLH, a partner category, or a prize format. ## Projects and Judging ### Do I Need to Create the MLH Partner Challenge? No. MLH assigns the partner challenge and it appears automatically on the event's Challenges page and project submission form. Organizers may add a separate local category by following [Confirm the Event Challenges](/run-your-event/organizerhq-tutorial.md#confirm-the-event-challenges). ### Does Every Project Need to Be in OrganizerHQ? Every team presenting a project must submit it through OrganizerHQ. Teams must additionally select each eligible partner challenge they are entering. ### Can We Also Use Devpost or a Judging Spreadsheet? You may use an external tool as an optional judging aid. It does not replace the required OrganizerHQ project submissions, challenge selections, check-ins, or winner declarations. ### What If a Team Misses the Submission Deadline? A project must appear in OrganizerHQ before it is judged. If the event schedule allows, ask the team to submit and apply the same deadline policy to every team. ### What If No Project Is Eligible for a Partner Category? Do not declare an ineligible project simply to fill the category. Document the issue and contact before announcing a result. ## Funding and Prizes ### Can We Spend the Full Allowance Regardless of Attendance? No. The maximum reimbursement is based on verified OrganizerHQ check-ins, capped at 50 hackers, and MLH cannot reimburse more than the approved, itemized amount actually spent. See [Receipts and Reimbursement](/close-out-your-event/reimbursements.md). ### Will Winners Receive Physical Prizes? Not always. Depending on availability and onboarding instructions, winners may receive digital gift cards instead. Do not promise a format until MLH confirms it for the event. ### What If a Prize or Reimbursement Is Delayed? Email with the event name and the relevant project, category, reimbursement, or prize details. Do not send unnecessary attendee financial or identity information by email. ## Contact Email the Hack Days team at . Include the OrganizerHQ event name and a concise description of the issue. For urgent safety or Code of Conduct incidents, use the reporting information in the [MLH Code of Conduct](https://github.com/MLH/mlh-policies/blob/main/code-of-conduct.md).