Syncing Zelcore Across Your Devices

You just unboxed a new phone. Zelcore is already running on your laptop, your balances are healthy, and everything feels familiar. You tap Sync in the app and expect something to happen automatically — some handshake between devices, a progress bar, maybe a two-factor prompt.

What actually happens: a text field appears asking for your seed phrase.

That's the whole mechanism. Zelcore's cross-device setup is a credential-import model, not a cloud sync. Your seed phrase is the transport. Understanding that distinction will make the next steps obvious — and will make you much harder to phish.

Before you start

• Have your written seed phrase backup at hand. Zelcore restores standard 12-, 18- or 24-word BIP-39 recovery phrases (Zelcore import guide). Enter whichever length your wallet gave you. If you haven't backed it up yet, stop here and read Backing Up and Recovering Your Zelcore Wallet first. For a seed phrase account, there is no other way to bring Zelcore to a new device.
• Still on a legacy username and password account? Legacy accounts still sign in on a new device with the same username and password, but that login is deprecated and will be phased out (Zelcore account types). We recommend moving your funds to a seed phrase account before you add another device.
• Install Zelcore from the official source. Desktop: zelcore.io. Mobile: the official app stores. Browser: the official extension. Always verify you're on a genuine listing: fake wallet apps have turned up on Google Play, and copycat websites push trojanized wallet apps to both Android and iPhone users (ESET Research).
• The new device needs a working internet connection. After you import your seed phrase, Zelcore reads your balances from the blockchains.
• Allow 5–15 minutes, depending on how many assets you hold and your connection speed.

This guide is for adding a second device to a wallet you already use. If you're setting up Zelcore for the first time, see Setting Up Zelcore for the First Time instead; for storing and testing your backup, see the backup guide linked above.

How Zelcore sync actually works

When you enter your seed phrase on a new device, Zelcore does three things:

1. Derives your wallet addresses using the BIP-44 standard — the same deterministic math your original device used. Given the same seed, Zelcore always produces the same addresses. Zelcore doesn't support an extra BIP-39 passphrase (a "25th word"), so the words alone are enough (Zelcore import guide).
2. Reads your balances and transaction history from the blockchains. That data lives on-chain; Zelcore fetches it through its own network connections and backend nodes rather than copying it from your other device.
3. Stores your encrypted credentials locally on the new device. Your seed phrase is not uploaded to a cloud service to sync it between devices.

Private keys you imported one by one (through Import a Wallet → Wallet Private Key) are the exception: they are stored only on the device where you imported them and are not part of your seed phrase (Zelcore import guide). Back each one up separately, and import it again on the new device.

In Zelcore: adding a second device

1. Open Zelcore on the new device and choose Sync/Register BIP44 Seed Phrase Account. On the next screen, do not tap Generate Seed Phrase: that creates a fresh seed phrase and a completely different set of addresses.
2. Select the word count of your seed phrase, then tap Import Seed Phrase. The app shows a numbered entry form with one field per word.
3. Enter your seed phrase word by word, in order, from your offline backup. Type carefully: most failed imports come from a single transposed or misspelled word. The BIP-39 wordlist is built so that the first four letters are enough to identify a word unambiguously (BIP-39 specification). If a word you typed isn't on the list, check it against your backup.
4. Set a Seed Label and a new Easy Login passphrase and, if your device supports it, enable biometric unlock. This is a local access control, separate from your seed phrase. It does not transfer between devices — you configure it fresh on each one.
5. Enter your d2FA PIN if Zelcore asks for it. If you turned on d2FA, the PIN is stored on the Flux blockchain, not on your device, so restoring the seed phrase does not reset it. Back up the PIN securely, in a separate place from your seed phrase backup.
6. Wait for the wallet to load. On the first login on a device, Zelcore runs Smartify to find the assets that hold balances. If you hold many coins, this can take a few minutes. A spinning indicator next to each asset means the balance is still loading.
7. Verify your balances match. Open two or three assets and confirm the amounts match what your original device shows. On-chain balances should be identical within seconds of a new block.

What comes back — and what doesn't

Funds held at your seed phrase addresses are accessible again. Your personalisations are not — those live only in local app storage — and neither are separately imported private keys until you import them again.

iOS note: Swaps, Buy, Sell and the NFT gallery work on iOS just as on Android and desktop. All wallet functions — send, receive, balance checking — work normally.

You'll know it worked when…

• Your balances on the new device match your original device.
• Tapping any asset shows the correct transaction history.
• You can generate a receive address and it matches the address shown on your original device.

If something goes wrong

"Seed phrase is invalid" or import fails immediately Check word order first: the Zelcore import guide lists incorrect word order and misspelled words among the possible causes of an "Invalid seed phrase" error (Zelcore import guide). Then check spelling: "abandon" vs "abondon", "acquire" vs "acuire". Compare each word against the BIP-39 English word list. Type the words from your offline backup rather than copying them through the clipboard, where other software on the device can read them.

Balances show zero or look wrong after import Run Smartify from Settings first; it refreshes the connection to Zelcore's backend nodes and resyncs balances (Zelcore balance troubleshooting). If still zero, check your internet connection. For less common assets, you may need to add the coin manually under Manage Assets. If a balance still differs, look up the address on a block explorer to see what the chain itself shows.

App asks for seed phrase again on relaunch You likely didn't complete the setup flow before closing the app. Go through the import steps again from the beginning.

Someone in a Telegram group or Discord DM says they can help you sync — and asks for your seed phrase That is a phishing attack. Zelcore support will never ask for your seed phrase, password, or private keys. No legitimate service, support agent, or website will ever ask you for your recovery phrase or private keys (ethereum.org security guide). Close the conversation and report it. Fake support impersonators, lookalike websites, and fraudulent giveaway accounts are the primary threat vector for crypto users. If you're unsure whether a site is genuine, check zelcore.io directly — do not follow links from DMs.

You lost your seed phrase before setting up the second device If your seed phrase is gone and your original device is also gone, the funds at your seed phrase addresses are permanently inaccessible. There is no server-side backup and no account recovery path. This is the non-negotiable cost of self-custody. Protect your written seed phrase accordingly.

One device at a time, the same way every time

Every platform — Windows, macOS, Linux, iOS, Android, browser extension — goes through exactly this flow. For a seed phrase account, the seed phrase is both the synchronisation key and the only recovery path. Keep it safe, keep it offline, and the same words will restore your wallet on any device, anywhere.