Share reject reasons: what the pool told your miner
Each numbered reply the pool sends when it declines a share, what it really means, and which ones point at something in your own setup you can fix.
What does a share reject reply tell you?
When the pool declines a share, it does not just say no. It sends back a numbered reason, and your miner prints it.
That one line turns an hour of random setting changes into a one-minute fix. So it is worth knowing what each reply means.
Some replies mean something is wrong at your end. Some mean nothing is wrong at all. Reading them all the same way is how people end up re-flashing a card that was fine.
The five replies in short
- 20, other: read the text beside the number.
- 21, job not found: a stale share, and a small number is normal.
- 22, duplicate: counted once and never held against you.
- 23, low difficulty: usually a problem at your end.
- 24, unauthorized: almost always the wallet address.
21, job not found
The work your share answered had already expired. The network moved on while the share was in flight. By the time it arrived, its question already had a winner.
This is the stale share. A small number of them is the cost of being on the internet, because light through fibre is not instant.
Act on it only when it stops being small. A rate that climbs week after week points at latency. Try the region closest to you and a wired connection before anything else.
A rate that jumps the moment you add a rig points at that rig.
23, low difficulty
Your share did not reach the target it was given. This reply usually means something at your end. It is the first place to look when rejects appear.
Check these causes:
- An unstable overclock. Work that fails verification only sometimes is the classic sign: a few percent of shares, not every one. Drop the core and memory clocks to stock and see whether the rejects go too.
- The wrong algorithm. A miner started on the wrong one produces almost nothing that can pass. So this shows up as rejects everywhere, not a few percent.
- An out-of-date miner. After a network upgrade, an old build keeps producing work under the old rules. Every share of it fails.
- A fixed difficulty you set too high by hand. If you pinned one, remove it and let the pool tune your pace.
22, duplicate, and why it is not held against you
The same share reached the pool twice. It is counted once, which is correct. After that, nothing happens: a duplicate never counts as a bad share and never moves you toward a ban.
This is a deliberate choice, not an oversight. Duplicates are usually the hardware being hardware.
- ASIC firmware (the software inside a dedicated mining machine) retries a submission it thinks was lost.
- A proxy layer re-sends a share.
- A miner that finds the same answer twice for the same work sends it twice.
None of that is the miner cheating. Pools that treat duplicates as invalid quietly punish rigs for behaviour their firmware chose.
If duplicates are constant rather than occasional, two rigs usually share one worker name. Give every rig its own.
24, unauthorized
The login was not accepted, or a share arrived before the login was. In practice this is almost always the wallet address.
The address may have a typo, or a space that came along with a copy and paste. Or it may belong to a different network than the one you are pointed at.
The pool tries to say which. If an address is valid but belongs to another network, the reply says so. It also names the network this pool is on.
A wrong network and a typo look identical in a log. They need completely different fixes.
20, other
This covers everything that is not one of the four above. The reply carries text beside the number that says what happened. So you read this one rather than look it up.
Two of these replies are worth knowing, because they are policy rather than a fault in your work. Both follow a stale rate that stays high for a long time:
- First, stale shares are rejected outright.
- After that comes a temporary ban.
Both replies say plainly that stale shares are the reason. They are not a verdict on your hardware. The pool is declining to keep paying for work that cannot pay.
Both clear on their own once the rate comes back down.
How many rejects are too many?
For job not found, under 1 percent is healthy on a well-chosen region. Nothing reaches zero, so watch the trend rather than the count.
For low difficulty, any steady amount means something is wrong. It is not a cost of being online. It is work that failed verification, and it earns nothing.
A rig at a few percent is a rig with an overclock to walk back.
The Live tab of your dashboard shows both as they happen. It lists every share as the pool judges it.
What if the reply does not tell you enough?
Work through the checklist in the rejected shares article. It orders the causes by how often each turns out to be the culprit.
If one rig rejects and the others are clean, the problem is that machine, not the pool. Suspect its overclock profile first, then its driver version, then its riser cables.