How do I withdraw my remaining 1 DOT?
Warning: if your DOT balance goes lower than 1, the rest will be destroyed. Before making any transactions with your DOT, please read the Why do I have to make an extra deposit? section.
What is existential deposit?
On the Polkadot network, 1 DOT is the so-called "existential deposit" needed to keep your account alive. If your balance goes lower than 1, your account will get deactivated. You can always bring it back by sending at least 1 DOT to your address.
How to withdraw my 1 DOT?
Starting with Atomic Wallet v2.27.0 (or 0.72.0 for mobile), the 1 DOT existential deposit is now available for withdrawal. You'll still need to pay the network fee charged by the Polkadot blockchain, though, which usually amounts to about 0.02 DOT. The fee cannot be deducted from your remaining 1 DOT, so just make a small DOT deposit to withdraw everything.
Why do I have to make an extra deposit?
Once your DOT account's balance goes lower than 1, the remaining DOT will be purged by the blockchain. That's why the network fee cannot be paid with just the remaining 1 DOT. If you were to send [1 - 0.02 = 0.98] DOT out, it would automatically get your account deactivated and your remaining funds reaped.