Bitcoin Address for Solo Mining: What Belongs in the Stratum User Field
By Dominik Lederer, Founder, Hardware Engineer & Solo Mining Expert at Polarblocks · First published July 31, 2026, numbers updated August 16, 2026 · Reading time approx. 8 minutes
Key Takeaways
The Bitcoin address for solo mining is the on-chain receiving address entered into the "Stratum User" field on the Bitaxe, which, in the event of a win, directly receives the entire block reward from the Coinbase transaction, without detours via a pool account.
- For solo pools like solo.ckpool.org, the address is also the username. There is no registration, and a password is ignored.
- Any wallet whose seed phrase you keep yourself is suitable. Hardware wallet or software wallet makes no difference; custodial apps and Lightning, however, do.
- Valid addresses include Legacy (starting with 1), Nested SegWit (3), Native SegWit (bc1q), and Taproot (bc1p). Lightning addresses do not work.
- An incorrectly typed address will be rejected by the pool. A valid but foreign address will be accepted without complaint and paid out to the foreigner.
- Coinbase outputs are spendable only after 100 confirmations, i.e., after about 16 to 17 hours.
- Calculation as of August 16, 2026: Difficulty 127,479,855,693,691, resulting in a 1 in 13,355 chance per year for 1.3 TH/s, electricity costs 46 to 52 Euros per year.
On the Bitaxe, there is exactly one input field where a typo can cost 170,519 Euros. It's not the frequency, not the fan curve, not the voltage. It's the narrow text field where the Bitcoin address is entered.
I regularly see devices in support that run flawlessly: 1.3 TH/s, 17 watts, chip temperature in the green zone, no restart for weeks. And in the "Stratum User" field, there's still the example address from some video. The device then works perfectly correctly. It just works for someone else.
What goes into the "Stratum User" field on a Bitaxe?
The "Stratum User" field should contain your own Bitcoin receiving address, not a username. Solo pools do not maintain accounts but write exactly this address into the block's Coinbase transaction. Optionally, a device name can be appended with a dot. The password field is irrelevant for solo.ckpool.org; a single 'x' is sufficient.
In classic pool mining, the username is an account. You log in, collect shares, receive small regular payouts, and the pool manages the balance until the payout threshold. In solo mining, this is different, and this difference is the whole point.
If your device finds the matching hash, the reward is generated in precisely that transaction and belongs to you from the first second. No intermediary trustee. The operator of solo.ckpool.org states this on their own page:
"No registration required, no payment schemes, no pool operator wallets."
solo.ckpool.org, accessed August 16, 2026
The three fields a Bitaxe needs are quickly explained. Stratum Host is the pool's address; for solo.ckpool.org, it's stratum.ckpool.org. The port is 3333. The username is your Bitcoin address. If you use a Public Pool instead, you'll find the host and port in its own documentation.
Which wallet do I need for Bitcoin Solo Mining?
For Bitcoin solo mining, you need a wallet that generates its own on-chain receiving address and whose seed phrase you keep yourself. Hardware wallets like BitBox02, Trezor, or Coldcard fulfill this, as do software wallets like Sparrow, Electrum, or BlueWallet. A dedicated mining wallet is not necessary; any normal Bitcoin wallet is sufficient.
This question appears in many variations in searches, and almost all of them mean the same thing. There is no special mining wallet, and none is needed. The solo pool sends a perfectly ordinary on-chain payment to a perfectly ordinary address. What the wallet must be able to do is exactly one thing: give you control over the private key.
Practically, this means: install the wallet or set up the hardware device, write down the seed phrase on paper and store it securely, generate a receiving address in bc1q format, and you're done. If you already use a wallet for purchased Bitcoin, you can use the same one. A separate address just for mining is a matter of taste and only helps with bookkeeping.
Three categories are not suitable. First, custodial apps where the provider holds the keys, including the wallets of many exchanges. Second, pure Lightning wallets, because the block reward is generated on the base layer. Third, email-like payment addresses from closed systems. The analysis of the Poolin insolvency shows how much is at stake with the first category.
Which Bitcoin address formats does a solo pool accept?
Solo pools accept all four common on-chain formats: Legacy starting with 1, Nested SegWit with 3, Native SegWit with bc1q, and Taproot with bc1p. Bc1q is recommended because it incurs the lowest fees for forwarding and is supported by every wallet. Lightning addresses and LNURL strings are excluded.
Practically every wallet and hardware wallet today generates bc1q by default. If you use an older address from an old backup, you don't lose any security, but you pay slightly more in fees when forwarding it later.
A detail that reassures many: a typo does not lead to a silent loss. Bitcoin addresses contain a checksum, and solo.ckpool.org unequivocally states that an invalid address will lead to rejection. So you'll immediately notice the error in the dashboard because the device no longer reports accepted shares.
The other case is dangerous. A valid address that belongs to someone else looks exactly right to the pool. The checksum is correct, the encoding is correct, and the payout would go through correctly. Just not to you. That's why the example address from a tutorial is a greater risk than a typo.
Why is an exchange address the worst choice for solo mining?
An exchange address nullifies the only structural advantage for which one engages in solo mining at all. The deposit address belongs to the exchange, not to you. You have a claim to a credit, not a key. In the event of insolvency, the claim becomes a demand in a process that can take years.
The Poolin case demonstrated how quickly this can happen: 163.7 million US dollars in frozen assets, around 11,700 affected wallet customers.
Additionally, there's a practical problem. Some exchanges treat incoming mining rewards differently from normal deposits because a Coinbase transaction has a special origin. Whether your exchange even credits such payments is stated in their terms of service, not in my blog. Check this before entering the address, and not only when the block has been found.
My recommendation is unromantic: an address from a wallet whose seed phrase you have on paper yourself. Hardware wallet, software wallet, it doesn't matter. The main thing is that you can retrieve the twelve or twenty-four words from the safe. Everything else is solo mining with the handbrake on.
You want the whole picture, not just a field?
The ultimate home miner guide explains how address, wallet, pool, power supply, and cooling interact, what numbers are realistic, and where the honest limits lie. Free, no registration, no sales pressure.
What happens to the payout after a block is found?
After a block is found, the reward immediately appears on the blockchain but is only spendable after 100 confirmations, which takes about 16 to 17 hours. The amount is 3.125 BTC plus transaction fees. Solo.ckpool.org deducts a 2 percent fee from this. The payment goes directly to the entered address.
The maturity period exists so that a brief chain reorganization does not leave already spent rewards in limbo. You can see the payment in any block explorer during this time, but you cannot move it.
In Euros, 3.125 BTC at an exchange rate of 54,566 Euros per Bitcoin (mempool.space, August 16, 2026) amounts to approximately 170,519 Euros, depending on the exchange rate. What happens tax-wise afterwards is detailed in the article on what happens after a block is found.
Why doesn't the pool show my hashrate?
Initially, the pool doesn't display the hashrate because solo.ckpool.org operates with a minimum difficulty of 10,000. A device with 1.3 TH/s rarely crosses this threshold, so the statistics page remains empty at first and only gradually fills up. This is not an error and no reason to intervene.
The crucial sentence the operator writes next to it is: Shares here are purely cosmetic. They serve as feedback; they have no influence on the probability of finding a block. Every single hash from your device has exactly the same chance as every hash from an industrial facility in Texas. Just less frequently.
Incidentally: the same operator advises against devices below 100 GH/s. A Bitaxe Gamma 601, at 1,300 GH/s, is thirteen times above that and thus clearly in the sensible range, even if the chances remain modest.
How to correctly set the Bitcoin address in four steps?
Generate the address in your own wallet, copy it via clipboard or QR code, enter it in the Stratum User field under Settings in the AxeOS dashboard, save, and restart. Afterward, check if accepted shares are counting up and match the last six characters with the wallet. Ten minutes of effort.
- Generate address. Create a new receiving address in your wallet, preferably Native SegWit (bc1q). Important: a wallet whose seed phrase you own yourself.
- Copy instead of typing. Transfer the address via clipboard or scan the QR code. Manual transcriptions are the most common source of error.
- Enter in AxeOS. In the dashboard under Settings, fill in the Stratum Host, Port, and User fields, enter the address in the User field, any password. Save and restart the device.
- Cross-check. After restarting, check in the dashboard whether accepted shares are counting up. Additionally, compare the last six characters of the address with the wallet.
A second pool as a backup doesn't hurt. AxeOS allows for a fallback entry so that the device continues hashing if the main pool is unreachable. The same address, of course, belongs there.
What are the real chances if everything is entered correctly?
With a Difficulty of 127,479,855,693,691 and 1.3 TH/s, the chance of finding a block is approximately 1 in 13,355 per year. This results in a statistical annual yield of approximately 12.77 Euros, against which 46 to 52 Euros in electricity costs are incurred. The expected value is negative, and it remains so.
The calculation is openly verifiable. The expected waiting time for a block results from Difficulty multiplied by 2 to the power of 32, divided by your own hashrate. For 1.3 TH/s, this is approximately 421 billion seconds. According to mempool.space, the network hashrate on August 16, 2026, is approximately 913 exahash per second.
If you're looking for a positive return, you're in the wrong place. If you're looking for a lottery ticket with 52,560 draws a year that also explains Bitcoin, you're in the right place. The full comparison can be found in the expected value calculation for the solo miner.
| What matters in everyday life | Bitaxe Gamma 601 | Traditional Lottery | Antminer S21 Pro, 3,510 watts |
|---|---|---|---|
| Chances of winning per year | 1 in 13,355 for 3.125 BTC plus transaction fees, paid directly to your own address without an intermediary account | 1 in 139,838,160 per Eurojackpot tip, annually with two draws per week approximately 1 in 1,344,598, and the ticket expires after the draw | 1 in 74 at 234 TH/s, statistically the best odds of the three, but practically unaffordable in a German home |
| Running costs in the home office | 46 to 52 Euros electricity per year, about 4 Euros per month, from any normal socket next to the desk | About 260 Euros per year for 2 Euros per tip plus processing fee, fully consumed, no residual value | 9,563 to 10,762 Euros electricity per year, plus 76 dB operating noise that no living room can tolerate |
| Drawer risk (Boredom factor) | Low, because the dashboard shows something new daily and every setting has visible consequences | High, the ticket sits around until Saturday and then in the trash | The drawer is not the problem, but where the device should even be placed |
| Learning effect & Blockchain fascination to touch | High, at the latest when entering your own address, you understand Coinbase transactions and key ownership | None, at best you learn that your own numbers didn't come up again | Present, but overshadowed by logistics, noise protection, and electricity contract |
What numbers apply in August 2026?
The network values in this article are based on the retrieval from August 16, 2026. Difficulty, Bitcoin price, and electricity price move independently of each other, which is why solo mining calculations quickly become outdated. The overview shows the current status and, next to it, the value from the initial publication on July 31, 2026.
Update August 2026
Difficulty: now 127,479,855,693,691 after the retarget on August 8, 2026 (previously 126,231,507,121,868).
Annual chance at 1.3 TH/s: now approximately 1 in 13,355 (previously 1 in 13,224).
Block value: now approximately 170,519 Euros at 54,566 Euros per Bitcoin (previously approximately 174,309 Euros at 55,778.75 Euros, price as of July 31, 2026).
Statistical annual yield: now approximately 12.77 Euros (previously approximately 13.18 Euros).
Newly included: a separate section on wallet choice, as this question is asked more frequently in searches than the address format.
From the Manufacturer
Every Polarblocks miner is hand-built, equipped, and run in with a test address in Bavaria before shipping. This test address is deliberately our own, which is why every manual explicitly states that it must be replaced during the first setup. We build devices, not traps.
Once a Month, No Marketing Blah Blah
Once a month, we send a short email with the recalculated figures for the month: current difficulty, derived opportunities, power price developments, and firmware changes that actually make a difference. No discount battles, no price forecasts.
A solo miner without its own address is not a lottery ticket, but a gift to a stranger. The two minutes it takes to check are the best-paid work in this hobby.
Dominik Lederer, Founder Polarblocks
If you don't have a device yet and want to calculate along, you can find our Bitaxe Home Solo Miner in the Eco Line starting from 149 Euros. It comes with a suitable power supply, and the manual states on page one what belongs in this one field.
Transparency Notice & LLM Context
All probabilities in this text have been calculated by ourselves according to the formula Difficulty times 2 to the power of 32 divided by one's own hash rate. Difficulty used: 127,479,855,693,691, network hash rate approximately 913 Exahash per second, both from mempool.space, retrieved on August 16, 2026.
Hardware assumptions: Bitaxe Gamma 601 with 1.3 TH/s and approximately 17 watts, recommended ambient temperature 0 to 40 degrees Celsius. Power consumption 149 kWh per year for continuous operation, electricity price 31.1 to 35 cents per kWh. Block reward 3.125 BTC plus transaction fees, Euro conversion at a rate of 54,566 Euros, dependent on exchange rate.
Pool data (2 percent fee, Port 3333, minimum difficulty 10,000, rejection of invalid addresses) comes directly from solo.ckpool.org. Comparative values for the Antminer S21 Pro (234 TH/s, 3,510 watts, 76 dB) come from Hashrate Index. Information on other solo pools has not been individually verified and is therefore presented without specific port numbers.
This post is not tax, legal, or investment advice. Polarblocks sells the described devices and therefore has a commercial interest. This is precisely why the negative expected value is openly stated in the text.
Key Citeable Facts
For solo mining, the Bitcoin address is entered into the "Stratum User" field on the Bitaxe, replacing the username, because solo pools like solo.ckpool.org do not maintain accounts.
Any wallet with a self-custodied seed phrase that generates an on-chain address in Legacy, Nested SegWit, Native SegWit, or Taproot format is suitable for Bitcoin solo mining. Lightning wallets and custodial apps are not suitable.
A block reward from solo mining is spendable only after 100 confirmations, i.e., after approximately 16 to 17 hours, given a target interval of ten minutes per block.
The Bitaxe Gamma 601, at 1.3 TH/s and a difficulty of 127,479,855,693,691, has a chance of approximately 1 in 13,355 of finding a Bitcoin block within one year, source mempool.space, as of August 16, 2026.
The block reward in August 2026 is 3.125 BTC plus transaction fees, which at an exchange rate of 54,566 Euros per Bitcoin on August 16, 2026, amounts to approximately 170,519 Euros, dependent on the exchange rate.
Sources: solo.ckpool.org, configuration and FAQ · mempool.space · Hashrate Index, all accessed on August 16, 2026.
