Mnemonic seeds are based on the BIP39 (seeds) and BIP44 (accounts/multiple currencies).
When deriving addresses, one uses a derivation path to get to a specific addresses. The default paths are defined in the BIP specs, but some wallets may use different ones due to an error or intentionally (for instance, Ledger's Vertcoin derivation uses Monero's derivation path due to a coding error).
You can use tools such as Ian Coleman's BIP39 tool (preferably offline) to play around with your seed and derivation paths until you see your addresses. The tool has preloaded the common paths, so you should usually be able to access your wallet pretty easily, unless you were using an extremely unusual client.
Many wallets also publish their derivation paths in their support pages, and you could pull your original wallet's path from there.
Wallets such as Electrum will also let you import a seed and specify the derivation path, saving you from having to generate and import individual keys.
As long as your seed was generated by a wallet that complies with BIP44, and you are importing it into another wallet that also complies with BIP44, you should be able to recover all your keys with no additional work.
Strange, I tried recover with
CopayandElectrumfrom the same 12-word backup, and none of them could do it. – János – 2018-05-15T19:28:18.633Did you select Options->BIP39 when entering the seed in Electrum? Electrum will default to a non-BIP39 seed, so you must specify it explicitly. Have you ensured your derivation path is correct? – Raghav Sood – 2018-05-15T19:30:10.110
Yes, set BIP39. I think
CopayandElectrumhas the same 'derivation path'. Though I have no clue what it is good for.m/44'/0'/0'– János – 2018-05-15T19:32:55.933If you're confident the derivation path is correct, then your seed must be incorrect. It's hard to debug further without more details, but it also looks like copay is using a few non-standard paths: https://github.com/bitpay/copay/wiki I would try all of them, particularly
– Raghav Sood – 2018-05-15T19:40:01.983m/45'/2147483647/0/. Do you remember if your address starts with 1 or 3? If you were using a copay multisig, you will need more keys to recreate it in electrumAddresses in wallet start all with
1. – János – 2018-05-15T20:06:22.010@János if you have any extra word (passphrase) and you didn't set, you may get a different master key therefore addresses. – Adam – 2018-05-15T21:07:15.923