Skip to main content
SubWallet Extension enables cross-chain transfers, allowing you to move tokens between different blockchain networks. Whether transferring between Polkadot parachains or bridging to Ethereum, SubWallet handles the complexity for you.

​
What are Cross-Chain Transfers?

Cross-chain transfers move tokens from one blockchain network to another. For example:
  • Sending DOT from Polkadot to Moonbeam
  • Moving USDT from Ethereum to Polygon
  • Transferring KSM from Kusama to Asset Hub
These transfers use various bridging technologies to enable communication between different blockchains.

​
Types of Cross-Chain Transfers

SubWallet supports multiple cross-chain transfer methods.

​
XCM Transfers (Cross-Consensus Messaging)

Native cross-chain transfers within Polkadot and Kusama ecosystems:

Relay to Parachain

Send tokens from Polkadot/Kusama relay chains to their parachains.

Parachain to Relay

Transfer tokens from parachains back to the relay chain.

Parachain to Parachain

Direct transfers between parachains in the same ecosystem.

Asset Hub Routing

Transfers through Asset Hub as an intermediary between parachains.
XCM transfers within the Polkadot/Kusama ecosystem are typically fast (1-2 minutes) and have low fees compared to other bridging methods.

​
Cross-Ecosystem Bridges

Bridge between different blockchain ecosystems:
Connects Polkadot and Ethereum ecosystems. Bridge DOT, ETH, and other assets between networks.Transfer Time: 30-60 minutes
Fee: ~$5-70 depending on direction
Status: Beta (use with caution)

​
Initiating Cross-Chain Transfers

1

Select source network

Choose the blockchain network where your tokens currently exist.
2

Select destination network

Pick the network where you want to receive the tokens. SubWallet shows only compatible destinations.
3

Choose token and amount

Select which token to transfer and how much to send.
4

Enter destination address

Provide the receiving address on the destination network (often auto-filled if using the same account).
5

Review and confirm

Check transfer details, fees, and estimated time. Confirm the transaction.

​
Transfer Warnings and Confirmations

SubWallet provides warnings for complex or risky transfers:

​
Beta Features

Some cross-chain routes are in beta:
  • Asset Hub Bridges: High fees and beta status
  • Snowbridge: $5-70 fees, 30-60 minute transfers
  • New Routes: Recently launched transfer paths
Always start with small test amounts on beta routes.

​
Long Transfer Times

Some routes require extended processing:
  • Polygon Exit: Up to 3 hours + manual claim
  • Avail Bridge: Up to 90 minutes
  • Ethereum Finality: 12-15 minutes for sufficient confirmations
SubWallet warns you before initiating transfers with long wait times.

​
Manual Claiming

Certain bridges require you to claim tokens on the destination:
  1. Complete the transfer transaction on the source chain
  2. Wait for bridge processing
  3. Manually claim tokens on the destination chain
  4. Pay destination chain fees for the claim transaction
For bridges requiring manual claims, SubWallet provides transaction tracking and notifications when claims become available.

​
Cross-Chain Transfer Fees

​
Source Chain Fees

Transaction fees on the origin network:
  • Substrate Chains: Usually very low (0.01-0.1 DOT/KSM)
  • Ethereum: Can be high during congestion ($5-100+)
  • Layer 2s: Lower than Ethereum mainnet ($0.10-5)

​
Destination Chain Fees

Some transfers have destination fees:
  • Asset Reception: Automatic, included in source fee
  • Manual Claims: Separate transaction fee on destination
  • Bridge Fees: Fixed or percentage-based bridge service fees

​
Total Cost Example

Source Fee: 0.02 DOT (~$0.15)
Bridge Fee: None
Destination Fee: Automatic
Total: ~$0.15
Time: 1-2 minutes

​
Supported Transfer Routes

​
Within Polkadot Ecosystem

From Polkadot Relay Chain:
  • All Polkadot parachains (Moonbeam, Acala, Astar, Parallel, etc.)
  • Polkadot Asset Hub
From Polkadot Asset Hub:
  • Polkadot relay chain
  • All Polkadot parachains
  • Ethereum (via Snowbridge)
Between Polkadot Parachains:
  • Direct transfers (where supported)
  • Via Asset Hub routing

​
Within Kusama Ecosystem

From Kusama Relay Chain:
  • All Kusama parachains
  • Kusama Asset Hub
From Kusama Asset Hub:
  • Kusama relay chain
  • All Kusama parachains
Between Kusama Parachains:
  • Direct or routed via Asset Hub

​
Cross-Ecosystem Routes

Polkadot ↔ Ethereum:
  • Via Snowbridge (beta)
  • Via Chainflip (as a swap)
Ethereum ↔ Polygon:
  • Polygon PoS Bridge
  • Ethereum L2 bridges
Bitcoin ↔ Other Chains:
  • Via Chainflip swaps

​
Transfer Status and Tracking

Monitor your cross-chain transfers:

Initiated

Transfer transaction submitted on source chain

Processing

Bridge or relay system processing the transfer

Claiming

Ready to claim on destination (manual bridges only)

Completed

Tokens received on destination chain

​
Transaction History

View all cross-chain transfers:
  • Source and destination chains
  • Token type and amount
  • Transfer status
  • Transaction hashes for both chains
  • Timestamps and duration
  • Fees paid

​
Same-Account Transfers

When transferring within the same account (unified account):
  • Destination address auto-fills
  • No need to copy/paste addresses
  • Reduced error risk
  • Seamless cross-chain portfolio management
Unified accounts make cross-chain transfers incredibly easy - just select source network, destination network, and amount. Your addresses are handled automatically.

​
Different-Account Transfers

Sending to a different account or person:
  1. Verify Network Compatibility: Ensure recipient has an account on the destination chain
  2. Get Correct Address: Obtain the recipient’s address for the destination network
  3. Validate Address: SubWallet checks address format matches the destination
  4. Test First: Consider a small test transfer for large amounts
Always verify the destination address supports the token on that specific network. Sending to incompatible addresses can result in permanent loss of funds.

​
Existential Deposits

Substrate chains require minimum balances:
  • Existential Deposit: Minimum balance to keep account active
  • Transfer Limits: Can’t transfer below ED or account is deleted
  • First Transfer: First incoming transfer must meet ED to create account
Common Existential Deposits:
  • Polkadot: 1 DOT
  • Kusama: 0.0033 KSM
  • Asset Hub: 0.1 DOT/KSM
  • Most parachains: 0.01-0.1 of native token
SubWallet warns you if transfers would violate ED requirements.

​
Troubleshooting Cross-Chain Transfers

​
Transfer Taking Too Long

Verify the source transaction confirmed on the blockchain. Use block explorer links from SubWallet.
Some routes (Polygon exit, Snowbridge) take 30-90 minutes normally.
Some bridges require you to claim tokens on the destination. Check SubWallet notifications.
High traffic on source or destination chains can delay processing.

​
Transfer Failed

Ensure you have enough native tokens for transaction fees on the source chain.
Transfer amount may be below the minimum for that route. Increase the amount.
Verify the token is supported on the destination chain.
Transfer may violate existential deposit requirements. Adjust amount.

​
Tokens Not Received

  1. Verify Transaction: Check if source transaction succeeded
  2. Check Claim Status: Does it require manual claiming?
  3. Verify Address: Was the correct destination address used?
  4. Contact Support: For bridge issues, check bridge provider status

​
Advanced: Understanding XCM

XCM (Cross-Consensus Messaging) is Polkadot’s native interoperability protocol:

​
How XCM Works

1

Message creation

Source chain creates an XCM message describing the transfer.
2

Relay chain routing

Message passes through relay chain for verification and routing.
3

Destination execution

Destination chain receives and executes the message, minting/transferring tokens.

​
XCM Benefits

  • Trust-minimized: No external bridges or validators needed
  • Fast: Usually completes in 1-2 minutes
  • Low cost: Minimal fees compared to external bridges
  • Secure: Protected by relay chain and parachain security

​
Best Practices

Always test a new cross-chain route with a small amount first, especially for beta features or unfamiliar bridges.
Triple-check destination addresses when sending to external accounts. Cross-chain transfers are irreversible.
Be aware of expected durations. Don’t panic if transfers take the stated time to complete.
Maintain sufficient native tokens on both source and destination chains for fees and claims.
Read and understand any warnings SubWallet displays. Beta features may have higher risks or costs.
Track transfers using SubWallet’s status indicators and transaction history. Save transaction hashes.
Ensure first-time receives meet existential deposit minimums, and don’t transfer below ED from active accounts.
For external bridges, understand the provider’s security model, track record, and fee structure.

Build docs developers (and LLMs) love

Get started for freeTalk to us