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A new user often has no XLM to pay transaction fees or base reserves. If the user has a contract account, such as a passkey smart wallet, it can’t pay its own fees at all: contract accounts can’t sign transaction envelopes, so a separate G-account must act as the transaction source. There are three ways to cover these costs for a user. This guide compares them so you can choose one, or combine them.

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Compare the approaches

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When to use each

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Fee-bump transactions

Use a fee-bump transaction when the user signs their own transaction from a G-account and you want to pay the fee for it. A fee-bump also lets you raise the fee on a transaction that’s already signed, for example during surge pricing. The fee account pays the fee instead of the inner transaction’s source account, but the inner transaction still consumes the source account’s sequence number. A contract account can’t sign the inner transaction, so a fee-bump on its own doesn’t cover a contract account’s fees. Learn more in the Fee-bump transactions guide. Use sponsored reserves when a user’s G-account needs base reserves it can’t cover. Sponsorship can cover the account’s own two base reserves, so you can create the account with a starting balance of 0, and it can cover the subentries the account adds later, such as trustlines and signers. Both accounts sign the sponsorship transaction, so the user agrees to it. While the sponsorship exists, the reserves accumulate on the sponsoring account instead of the sponsored account. Smart contract data doesn’t require base reserves; it pays rent instead. A contract account is a smart contract, so sponsored reserves don’t cover its storage. Learn more in the Sponsored reserves guide.

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Relayers

Use a relayer when the user has a contract account, or when the user holds no XLM to pay fees. The user signs only the authorization entries for their contract call. The relayer rebuilds the transaction with its own G-account as the source account, pays the fees, and submits it. Rent for smart contract storage is part of the resource fee, so the relayer covers it too. You can run a relayer yourself, in which case you control its signer and fund the accounts that pay the fees, or you can use a managed relayer service. Learn more about the signing flow in Signing Soroban contract invocations.
Current recommendation (as of October 2026)For managed fee sponsorship, see the OpenZeppelin Relayer page. This recommendation changes over time; the page linked here stays current.

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Combining approaches

These approaches can work together:
  • Sponsored reserves and fee-bumps: a wallet that onboards G-accounts can sponsor each account’s reserves and fee-bump its transactions. To estimate the XLM you need for account creation, transaction fees, and trustlines, use the Stellar Wallet Sponsorship Calculator.
  • Relayers and fee-bumps: a relayer can wrap the transactions it submits in fee-bump transactions, which separates the account that spends the sequence number from the account that pays the fees. A relayer can also use channel accounts to submit transactions in parallel.