How can I make accessibility part of our sprint planning without it feeling like extra work nobody wants to do?
Stop treating accessibility as a separate task and start building it into the work you're already doing.
Here's how.
Instead of adding "Review accessibility" as a separate story on your board, include accessibility criteria in your existing acceptance criteria. When you write "User fills in and submits the contact form," add "using only a keyboard." It's the same feature, just built properly from the start.
When you estimate the story, factor accessibility into the original estimate rather than treating it as additional work. A login form that works for everyone might take a half day more. That's okay. That's the real cost of building it right.
Use your Definition of Done to make this automatic.
If stories must pass accessibility checks before they're considered complete, your team will stop seeing it as optional extra work and start seeing it as part of the job.
In time, they'll learn to spot accessibility requirements. When someone says "users need to upload documents," they'll automatically think about keyboard users, screen readers and error handling. It will become second nature.
The goal is to make accessibility invisible during planning because it's baked into everything you build.