Bitcoin Forum

Is it possible to receive a LN payment on Electrum if im only online on a watch only wallet on my phone?
I asked few ppl on other forums and nobody knew/answered this, lol...

I am not a specialist, so the following thoughts will be based on my own limited understanding of how the lightning network works. To receive and send payments on Lightning Network, you first need to open a payment channel with someone. Opening a channel means creating 2-of-2 multisig transaction where one of the keys belongs to you and the other to your counterparty. In order to sign your part of the transaction, your wallet should have access to a corresponding private key, which in the case of a watch-only wallet, it obviously doesn't have. So, from my understanding of what's going on, you can't create channels with watch-only wallets. Actually, I tried open a channel in watch-only Electrum, but it said "Lightning is not enabled for this wallet." I couldn't find an option to somehow enable it, maybe I should have funded my test wallet first, I don't know. It works with standard wallets, though, without changing any settings.

It works on the PC version so it might work on the Android version.

The steps (for the Desktop version) are:

• In your watching-only wallet copy of a 'Native SegWit' "bc1" Electrum wallet, go to "Wallet->Information" and enable lightning.
• Restart Electrum, then go to "Channels" tab, click "Open Channel" and fill-up the fields.
• After the last step, Electrum will prompt you to sign the PSBT (unsigned txn) using the main wallet just like what you're doing with the usual transaction.
• After broadcasting it, the channel should be established after 3 confirmations.

The steps (for Android version) should be similar [last steps untested]:

• In your 'Native SegWit' "bc1" watching-only wallet, tap the wallet name above to view its information.
• In the wallet info, tap "Not enabled" next to 'Lightning:', then read and accept the warnings, after that, Lightning is enabled.
• Go to "Menu->Channels" and open a channel (the rest of the steps are similar to the desktop version).

Note: The funds in your channel is separate from your on-chain funds so it's not protected by your cold-storage set-up.
Also, you cannot immediately be able to receive through lightning since you need to gain "inbound capacity" to do so;
one way to gain it is to use "reverse swap" which is available in the desktop version by clicking the switch "⇄" button in "swap", try tapping values/names in the Android version.
Swap/Reverse-swap costs on-chain transaction fee and the back-end's service fee though.