Lumens (XLM) are the native currency of the Stellar network. The lumen is the only token that doesn’t require an issuer or trustline, and it pays all transaction fees and covers minimum balances on the network.
To read up on the basics of lumens, head over to our Stellar Learn site: Stellar Learn: Lumens
Stellar requires a small fee for all transactions to prevent ledger spam and prioritize transactions during surge pricing. Transaction fees are paid in lumens.
To learn about fees on Stellar, see our Fees, Surge Pricing, and Fee Strategies Encyclopedia Entry
A unit of measurement used to calculate an account’s minimum balance. One base reserve is currently 0.5 XLM.
Validators can vote to change the base reserve, but that’s uncommon and should only happen every few years.
Stellar accounts must maintain a minimum balance to exist, which is calculated using the base reserve. An account must always maintain a minimum balance of two base reserves (currently 1 XLM). Every subentry after that requires an additional base reserve (currently 0.5 XLM) and increases the account’s minimum balance. Subentries include trustlines (for both traditional assets and pool shares), offers, signers, and data entries. An account cannot have more than 1,000 subentries.
Data also lives on the ledger as ledger entries. Ledger entries include claimable balances (which require a base reserve per claimant) and liquidity pool deposits and withdrawals.
For example, an account with one trustline, two offers, and a claimable balance with one claimant has a minimum balance of:
2 base reserves (1 XLM) + 3 subentries/base reserves (1.5 XLM) + 1 ledger entry/base reserve (1 XLM) = 3.5 XLM
When you close a subentry, the associated base reserve will be added to your available balance. An account must always pay its own minimum balance unless a subentry is being sponsored by another account. For information about this, see our Sponsored Reserves Encyclopedia Entry.