Overview

Y Combinator’s FAQ states that a single person can apply and that YC regularly accepts solo founders. The same FAQ still says one-person startups are tough and you are more likely to succeed with a co-founder. If you want a co-founder, YC runs Co-founder Matching. That is the official stance — not “solo is a feature YC prefers,” and not “YC never funds solo.”

This guide is educational. It is not a YC document. JoinAI is an independent community, not an official Anthropic or Y Combinator product.

Current window (retrieved 2026-09-15)

YC is accepting applications for the Winter 2027 batch (January–March in San Francisco). The on-time deadline is 2 November at 8pm PT; on-time applicants are told they will hear by 11 December. Late applications are still read, without a promised date. You can also apply to later batches via Early Decision. Interviews, if any, are by video in November and December. YC invests when you are accepted, not when the batch starts. The batch is in person at YC’s San Francisco campus. Source: ycombinator.com/apply — re-check before you write dates into a draft.

Standard deal (retrieved 2026-09-15)

YC’s published standard deal is $500,000: $125,000 for 7% on a post-money SAFE plus $375,000 on an uncapped MFN SAFE. Source: ycombinator.com/deal. Do not treat this as an offer from JoinAI.

Before you write

Confirm section names on the live form. YC updates questions. Do not copy a 2025 blog’s field list as if it were the form.

Paul Graham’s official essay (ycombinator.com/howtoapply) is still the best writing brief: be matter-of-fact; put the point in the first sentence; cut marketing-speak; be specific about what you have built.

One-sentence description

Write what you are building in the simplest terms: who it is for, what it does, why now. Weak: “An AI-native platform that empowers creators.” Stronger: “Automated compliance checking for SaaS privacy policies — it flags gaps between the policy and the product.” That style matches YC’s own “matter of fact” advice. It is not a quoted acceptance.

Solo founder answer

Official FAQ: they accept solo founders and still prefer you understand the risk. A defensive “I don’t need a co-founder” is not in any official guide. Name the operational risks (bus factor, coverage, morale) and the concrete mitigations you already run. If you are looking for a co-founder, say so and use YC’s matching product.

What you have built

Describe what exists, who has used it, and one number you can defend. Idea-stage applications are allowed (YC’s FAQ says not to wait) — then say honestly that it is an idea.

The founder video is not the demo

Official video page (ycombinator.com/video): one minute; nothing except the founders talking; not a demo or promotional video. The demo has a separate field. All founders on camera (or a recorded call). Do not read a script. Putting a product walkthrough inside this minute contradicts YC. See the companion guide on this site for recording notes.

After you submit

YC’s FAQ encourages reapplication; they say a typical batch includes many companies that applied more than once. If you get an interview, answer as the company — you are the team.

Pre-submit (process, not magic)

Description a stranger can repeat
Live form fields filled; no leftover “TBD”
Traction or an honest “none yet”
Solo risks named without apology-theatre
Founder video ≤ 1:00, founders talking only, unlisted link works in an incognito window
Demo (if any) in the demo field, not the founder video
Dates and deal terms re-checked on ycombinator.com the day you submit

Independent community. Not an official Anthropic, Y Combinator, Techstars, Antler, OpenAI, AWS, or Google product. Program names belong to their owners. Listings are informational, not endorsements. Educational only — not legal, tax, or investment advice. Confirm the live form. Contact: hi@joinai.me.