These two words get used as if they mean the same thing. They do not, and the difference is the single most useful thing you can know before buying used golf balls from anybody.
Recycled — what we sell
A recycled ball is the original ball, found and cleaned. We wash it, we grade it, and that is it. The cover is the cover it left the factory with. The core, the compression and the dimple pattern are untouched. It performs like the ball it was built to be, because it is still that ball.
Refurbished — what we do not sell
A refurbished ball has had its original cover stripped and been repainted and reprinted to look new. It comes out of that process looking better than a recycled ball of the same age, which is exactly the point — and it is also why people get caught out.
The problem is what the paint does. It adds weight the ball was not designed to carry and it fills in the surface the cover relies on. Independent testing has repeatedly found refurbished balls losing meaningful distance and spin against both new and recycled versions of the same model. You are paying for a ball that looks newer and plays worse.
How to tell
Refurbished balls are usually sold under exactly that word, or under "restored", "re-painted" or "like new, refinished". If a listing advertises a perfect-looking premium ball at a price that seems impossible, and it never mentions grading, that is the one to ask about.
Our position
We will never strip or repaint a ball. If one comes to us too far gone to sell honestly, it goes in Hit-Aways or it goes in the bin. We would rather sell you a ball with a scuff on it and tell you about the scuff.
The number worth remembering
Robot testing has put a mint recycled Pro V1 within roughly two yards of a brand new one. A new dozen runs around $58. Ours start at $21.