How small can a payment be while still adding value to your wallet?
You generally would not be able to receive a single satoshi.
The Bitcoin Protocol defines something known as a &quot;dust limit&quot;.
The exact value of this limit varies based on the receiving address type, but it is defined as the minimum amount of BTC required to spend an input for a given address type.
It is calculated by using a basic 1 input 1 output transaction consuming an input from that address type at the minimum acceptable fee level, and calculating its fee (minimum fee level * tx size).
This works out to 546 satoshis for traditional p2pkh addresses, and 294 for p2wpkh addresses.
Transactions that create one or more outputs under the dust limit will be rejected by the network and you will not be able to broadcast them (even if other outputs in the transaction are above the dust limit). If you're left with a value under the dust limit as change, most wallets will add it to the fee.