Minimum Balance
This doc explains minimum balance requirements. If you want to know about transaction fees, check out the Fees doc.
All Bantu accounts must maintain a minimum balance of lumens. The minimum balance is calculated using the base reserve, which is currently 0.5 native tokens:
Minimum Balance = (2 + # of entries + # of sponsoring entries - # of sponsored entries) * base reserve
The absolute minimum balance for an account is 1 native tokens, which is equal to (2 + 0 entries) * 0.5 base reserve. Each additional entry reserves an additional 0.5 native tokens. Entries include:
- Trustlines
- Offers
- Signers
- Data entries
For example, an account with 1 trustline and 2 offers would have a minimum balance of (2 + 3 entries) * 0.5 base reserve = 2.5 native tokens.
Sponsored Reserves will affect the # of sponsoring entries and # of sponsored entries.
Claimable Balances are reflected in the # of sponsoring entries. Each claimant in a claimable balance will require an additional 0.5 native tokens. For example, an account that creates a claimable balance with 2 claimants would have a minimum balance of (2 + 0 entries + 2 sponsoring entries) * 0.5 base reserve = 2 native tokens.
Any transaction that would reduce an account’s balance to less than the minimum will be rejected with an INSUFFICIENT_BALANCE error. Likewise, lumen selling liabilities that would reduce an account’s balance to less than the minimum plus lumen selling liabilities will be rejected with an INSUFFICIENT_BALANCE error.
The minimum balance is held in reserve, and closing an entry frees up the associated base reserve. For instance: if you zero-out a non-lumen balance and close the associated trustline, the 0.5 native tokens base reserve that secured that trustline is added to your available balance.
Changes to Transaction Fees and Minimum Balances
Validators can vote to change the base reserve — just as they can vote to change ledger limits and and the minimum base fee — but that’s relatively uncommon. It should only happen every few years. For the most part, you can think of the base reserve as a fixed value. When it is changed, the change works by the same consensus process as any transaction. For details, see versioning.