Protocol Fees
These are Offerbook’s cut, taken in the loan token (USDC). They apply at three stages of a loan.At loan start — 25% of estimated interest (paid by the borrower)
When a loan is opened (an offer is accepted), the program estimates the total interest for the full loan term. A fee equal to 25% of that estimated interest is taken immediately, paid in USDC by the borrower.How this works in practice:
- If a lender fills a borrow offer: the borrower receives the USDC amount minus the fee.
- If a borrower fills a lend offer: the borrower pays the fee right after receiving the USDC.
At repayment — 10% of interest (paid by the lender)
When the borrower repays the loan, the borrower pays the full interest to the lender. A fee equal to 10% of the interest is then deducted from the lender’s return.Example: On a 100 USDC loan with 1% interest (1 USDC), the lender receives 0.9 USDC in interest. The remaining 0.1 USDC goes to the protocol.
At collateral transfer — 0.1% of collateral (paid by the lender)
If the loan is not repaid after maturity and the lender claims the collateral, a 0.1% fee is deducted from the collateral before it is transferred to the lender.No fee is charged on collateral transfers involving NFT or RWA collateral.
Effective APR / APY
The interface displays the Effective APR (borrower side) and Effective APY (lender side) in the offer summary. These rates account for platform fees automatically. Effective APR is higher than the offer APR because the 25% upfront fee is added on top of the interest the borrower owes. Example: an offer at 30% APR becomes 37.5% Effective APR (30% × 1.25). Effective APY is lower than the offer APY because the 10% fee is deducted from the interest received by the lender. Example: an offer at 5% APY becomes 4.5% Effective APY (5% × 0.9).Interest on Early Repayment
Borrowers can repay at any time before maturity, but the full interest for the agreed loan duration is always owed. There is no partial interest or fee reduction for early repayment.Fee Summary
| Stage | Who pays | Fee | Basis |
|---|---|---|---|
| Loan start | Borrower | 25% | Estimated total interest (USDC) |
| Repayment | Lender (deducted from interest received) | 10% | Interest (USDC) |
| Collateral transfer | Lender (deducted from collateral received) | 0.1% | Collateral value (no fee on NFT/RWA) |
Understanding the Three Cost Types
It helps to separate the three different things you pay for on Offerbook. They behave differently: two are gone for good, one comes back to you.Network fee
The Solana “gas” fee, paid on every transaction. Tiny (around 0.000005 SOL per signature). Never refunded.
Account rent
A deposit, not a fee. Solana requires you to fund any new account you create. Refunded when that account is later closed.
Protocol fee
Offerbook’s cut, taken in the loan token (usually USDC). Never refunded (a share may go to a referrer).
Rule of thumb: fees are gone, rent comes back. The largest SOL numbers you see when using Offerbook are usually rent (a refundable deposit), not a cost.
Account Rent
Account rent is a refundable deposit fixed by account type. The amounts are determined by Solana and do not change.| Account | Rent (SOL) | Paid when | Refundable? |
|---|---|---|---|
| User account | 0.00233856 | First time you use Offerbook | Not currently (expected to change) |
| Escrow account (per asset) | 0.00203928 | First time you deposit a given asset | Yes — when you withdraw the asset |
| Offer account | 0.00940992 | Each time you create an offer | Yes — when the offer is filled, cancelled, or expires |
| Loan account | 0.00651456 | When a loan opens | Not currently (expected to change) |
A separate escrow account is required for each different asset you deposit, so borrowers typically open more of them over time than lenders, who generally only need one for USDC. Opening a loan also creates a small additional account that is refunded when the loan is repaid or the collateral is claimed.
Referral Program
Offerbook offers a referral system where protocol fees can be split into referral rewards. The referral system applies at every stage where a fee is charged (loan start, repayment, collateral transfer).Default Fee Split
| Recipient | Share |
|---|---|
| Referred user | 20% of the fee |
| Referrer | 30% of the fee |
| Protocol | 50% of the fee |
How Referrals Work Across a Loan
The referred user benefit goes to the side that is paying or receiving at that moment:| Stage | Referred user benefit goes to |
|---|---|
| Loan start (25% fee) | Borrower |
| Repayment (10% fee) | Lender |
| Collateral transfer (0.1% fee) | Lender |
When Both Sides Are Referred
- If only one side of the loan was referred, that side’s referrer gets the full 30% referrer share.
- If both sides were referred, the 30% referrer share is split equally between the two referrers (15% each).
- The lender receives a $2 rebate (20% referred user share, since the lender is the one receiving at repayment)
- The borrower’s referrer earns $3 (30% referrer share, since only the borrower was referred)
- The protocol retains $5 (50%)
For details on how to create your share link, customize your vanity slug, and claim rewards, see Affiliate & Referrals.