For security reasons, we require a digital asset/cryptocurrency deposit to receive a number of confirmations on its blockchain before the funds can be credited to your account.
What are confirmations?
When a transaction is broadcasted to the network, it has to wait to be included in a block by the miners. Once a transaction has been included in a mined block, the transaction has received 1 confirmation. With each subsequent block, the number of confirmations increases for the transaction.
Why are there confirmation requirements?
To avoid the risks of reorganisations (reorgs) of blocks. That is why it is necessary to wait for a specific number of confirmations. Also, double spending can be avoided when funds aren’t credited until a certain number of confirmations have taken place (as listed further below).
The more confirmations received, the more permanent/irreversible the transaction is.
ETH & ERC-20 tokens validations
Prior to the Ethereum Merge, the number of block confirmations determined the amount of time required for a top-up over the Ethereum network to be reflected. Currently, each transaction is reflected only when the status of the block containing it is ‘Finalized’. Down below, you can learn about the lifecycle of ERC-20 deposits:
- First, a validator has to propose a block, containing transactions. There is a 12-second Slot in which a validator has time to propose a block. Up to 32 blocks can be proposed but some slots can remain unfilled.
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Then, the validators will vote on this group of blocks called ‘Epoch’. Every block will be first set in motion with the status ‘Unfinalized’.
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Afterwards, the block will be transitioned to the status ‘Unfinalized (Safe)’. This is the final stage before the block is validated.
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If the block is validated during the ‘Attestation’ phase, its status will change to ‘Finalized’. Once in that status, all incoming deposits to the Nexo platform contained within the block will be reflected.
What ERC-20 assets are supported on Nexo?
ETH, PAXG, USDT, USDC, DAI, NEXO, TUSD, USDP, BUSD, LINK, UNI, AXS, SAND, MANA, GALA, SUSHI, CRV, AAVE, APE, 1INCH, MKR, HT, FTT, MATIC, SWEAT, LDO, ENS, GMT, COMP, SNX, GRT, CHZ, CVX, DYDX, FXS
How long do confirmations take for the remaining networks?
Each block is found at a different rate depending on the blockchain.
For example, on the Bitcoin blockchain, a block is mined on average every 10 minutes, and Nexo only credits Bitcoin deposits to a client’s account after a minimum of 3 confirmations, which takes approximately 30 minutes.
However, sometimes when the network is heavily used, it can take Bitcoin miners 30 or even 60 minutes to mine a single block (1 confirmation).
As explained above, the time required for blocks to be included in the blockchain may increase significantly when the network is overloaded due to high demand. This inevitably leads to delayed transactions. One thing that can speed up your transfers to Nexo is opting for higher mining fees (gas fee) which usually leads to quicker blockchain confirmations.
| Asset | Number of confirmations |
| BTC (Bitcoin) | 3 confirmations |
| ETH, LINK, USDT, USDC, DAI, AAVE, SUSHI (Polygon network) |
200 confirmations
|
| MATIC (Polygon) |
127 confirmations
|
| BNB, BUSD (Binance Smart Chain) |
70 confirmations
|
| XRP (Ripple), XLM (Stellar), BNB, NEXO BEP2, and EOS | near-instant |
| BCH (Bitcoin Cash) | 15 confirmations |
| LTC (Litecoin) | 12 confirmations |
| TRX (Tron) | 20 confirmations |
| DOGE (Dogecoin) | 10 confirmations |
| ADA (Cardano) | 1 confirmation |
| DOT (Polkadot) | 2 confirmations |
Important:
- Nexo does not support SWEAT transfers over the NEAR network.