The HC Net requires small fees on transactions and minimum balances on accounts in order to prevent people from overwhelming the network and to aid in prioritization.
There are two special values used to calculate fees:
The fee for a transaction is the number of operations the transaction contains multiplied by the base fee, which is 100 Jots (0.00001 HCX).
For example, a transaction that allows trust on an account’s trustline (operation 1) and sends a payment to that account (operation 2) would have a fee of 2 × base fee = 200 jots.
HC Net deducts the entire fee from the transaction’s source account, regardless of which accounts are involved in each operation or who signed the transaction.
Each HC Net node usually limits the number of transactions that it will propose to the network when a ledger closes. If too many transactions are submitted, nodes propose the transactions with the highest fees for the ledger’s transaction set. Transactions that aren’t included are held for a future ledger, when fewer transactions are waiting.
See transaction life cycle for more information.
The fee pool is the lot of HCX collected from transaction fees.
HC Net does not retain these HCX. They are distributed in the weekly process of inflation voting.
If there are any unallocated HCX after the vote, those HCX return to the fee pool for dispersal in the next round.
All HC Net accounts must maintain a minimum balance of HCX. Any transaction that would reduce an account’s balance to less than the minimum will be rejected with an INSUFFICIENT_BALANCE error.
The minimum balance is calculated using the base reserve, which is 0.5 HCX:
The minimum balance for a basic account is 2 × base reserve. Each additional entry costs the base reserve. Entries include:
For example, an account with 1 trustline and 2 offers would have a minimum balance of (2 + 3) ×base reserve = 2.5 HCX.
Starting in protocol version 10, an account may also have HCX selling liabilities that must be satisfied in addition to the minimum balance discussed above. In this case, any transaction that would reduce an account’s balance to less than the minimum plus HCX selling liabilities will be rejected with an INSUFFICIENT_BALANCE error.
The base reserve and base fee can change, but should not do so more than once every several years. For the most part, you can think of them as fixed values. When they are changed, the change works by the same consensus process as any transaction. For details, see versioning.
The minimum balance is calculated using the base reserve, which is 0.5 HCX:
You can look up the current fees by checking the details of the latest ledger.Process