The absolute minimum balance for every active Stellar account is 1 XLM, therefore when making a payment you should make sure to leave at least 1 lumen in your account.
When activating your account with the initial payment, we recommend sending or buying at least 5 XLM to make sure you have enough to use LOBSTR app without any Stellar network restrictions.
Minimum balances help protect the network from spam account creation. Following the Stellar Network protocol, each new held asset (trustline), signer or active trade offer requires an additional 0.5 XLM reserve.
Sponsored Reserves also affect the minimum account balance and are reflected by the # of sponsoring entries and # of sponsored entries.
For example, an account with 1 trustline, 2 offers, 1 sponsoring entry, and 1 sponsored entry would have a minimum balance of 2.5 lumens:
1 XLM account min balance + 0.5 XLM base reserve * (3 entries + 1 sponsoring entry - 1 sponsored entry) = 2.5 total XLM reserve.
- Data entries
With reference to the Stellar Network protocol, when creating an offer for sale, the funds involved in the offer are postponed to the reserved balance and cannot be used until the order is canceled or executed.