- What is “Exact Payment”?
- When is “Exact Payment” mode needed?
- How do I calculate the amount to send?
- Step-by-step guide
- Calculation example
- FAQ
“Exact Payment” mode is designed for situations where the recipient must receive a strictly fixed bitcoin amount. Before using it, make sure you understand the math.
1. What is “Exact Payment”?
In standard mixer mode, the fee is deducted from the amount you send. That is, if you send 1 BTC at a fee of 4.5% + 0.0007 BTC, the recipient receives:
1 − (1 × 0,045) − 0,0007 = 0,9093 BTC
“Exact Payment” mode reverses the logic: you specify the amount that the destination address should receive, and the mixer computes how much you must send so that, after the fee, the recipient gets exactly that amount.
It is convenient, for example, when:
- You pay an invoice in BTC for a precise amount
- The exchange accepts only a strictly fixed amount
- Counterparty expects a specific BTC amount
2. When do you need “Exact Payment” mode?
Use “Exact Payment” if at least one of the following applies:
- The recipient is waiting for a specific BTC amount (agreed amount, invoice)
- You transfer funds to an exchange which strict amount requirements
- You can send slightly more than you intend to receive on the output
If you don’t need an exact output amount, use the standard “Mixer” mode. It is simpler and requires no precomputation.
3. How do I calculate the amount to send?
Formula for the amount to send:
Current fee parameters are shown on the mixer’s main page and in your Letter of Guarantee.
Important: Always check the parameters against current values on the site — the fee may change.
4. Step-by-step guide
Step 1. Open the mixer’s main page and choose the mode “Exact Payment” (third tab).
Step 2. Enter the recipient’s Bitcoin address in the “Destination address” field. Double-check the address — blockchain transactions are irreversible.
Step 3. Enter the desired receive amount in the “Amount to credit (BTC)” field. The mixer will automatically show how much BTC you need to send.
Step 4. Click “Create request” — you’ll be taken to the request page showing:
- Mixer deposit address
- QR code for mobile wallets
- Exact amount to send (including all fees)
- “Download Letter of Guarantee” button
Step 5. Be sure to download the Letter of Guarantee before sending coins. It contains all request parameters and is the only proof in any dispute.
Step 6. Send the amount stated in the request to the mixer address. The amount must match to the satoshi — any deviation will change the final result.
Step 7. Wait for the funds to arrive at the recipient address. Processing time is from a few minutes up to 6 hours.
5. Calculation example
Suppose the recipient expects exactly 0,5000 BTC. The current mixer fee is 4.5% + 0.0007 BTC.
Let’s calculate the amount to send:
amount_to_send = 0.5007 ÷ 0.955
amount_to_send = 0,52429... ≈ 0,5243 BTC
Therefore you need to send 0,5243 BTC to the mixer so the recipient gets exactly 0,5000 BTC after deduction of all fees.
The calculator on the request page does this math automatically — you don’t need to compute anything by hand.
6. FAQ
What if I send an amount different from the one stated in the request?
If you send less, the recipient receives less. If you send more, the excess is not returned — it goes to the shared pool for extra mixing. Always send the exact amount.
Can “Exact Payment” be used with multiple recipient addresses?
“Exact Payment” mode supports one recipient address. To split the amount across several addresses, use the standard “Mixer” mode.
Does the fee differ in “Exact Payment” mode?
No, the fee is the same for all modes. The only difference is the direction of the calculation: in the standard mode the fee is deducted from the amount sent; in “Exact Payment” it is added to the desired output.
How can I verify the mode is working correctly?
Try the free test: send 0.001 BTC and you’ll receive coins without any fee — proving the system works correctly.
