Interest on Prepaid Credits | Carolina Cloud Docs<br>Skip to content
Interest on Prepaid Credits
Your organization’s prepaid credits earn interest. We pay a SOFR-referenced rate, compounded daily, on the real-money balance an admin has purchased — the same way a bank pays interest on a deposit. Idle prepaid credit isn’t dead money: it grows until you spend it.
Interest is paid only on prepaid credits — the balance you bought (see Prepaid Credits). Free trial/promo credits never earn interest, which is one of the reasons the two buckets are tracked separately.
A credit, not cash<br>This interest is paid in Carolina Cloud credits , added to your prepaid balance to spend on compute and storage. It is not cash interest, not a cash deposit, and not redeemable for cash. Carolina Cloud is not a bank, and your prepaid balance is not a bank deposit or money-market account — “like a bank” describes the math, not a banking relationship.
The rate<br>Section titled “The rate”
The rate tracks SOFR (the Secured Overnight Financing Rate), the benchmark overnight interest rate published every business day by the Federal Reserve Bank of New York. By default we pay the full SOFR rate — no spread skimmed off — which typically beats what a bank pays on a comparable deposit, since banks usually pay SOFR minus a margin.
The interest you earn is itself added to your prepaid balance, so it’s fully spendable on compute and storage like any other prepaid credit.
The applied rate is never negative. If the reference rate ever went below zero, your interest simply stops at 0 — your balance is never reduced by interest.
How it’s calculated<br>Section titled “How it’s calculated”
We follow the standard bank/market convention so the numbers are auditable and reproducible:
Daily accrual on an ACT/360 day-count. Each day’s interest is balance × (annual rate ÷ 100) × (1 ÷ 360). SOFR is quoted on a 360-day year, so we use 360.
Daily compounding. Interest is capitalized into your prepaid balance every day, so the next day’s interest is calculated on the slightly larger balance. Over a year this makes the effective annual yield (APY) a touch higher than the headline rate.
Weekends and holidays are covered. SOFR only publishes on business days, so each non-business day accrues using the most recently published rate. Friday’s rate carries through Saturday and Sunday automatically — you earn interest every calendar day.
Banker’s rounding to the cent (8 decimal places), so accrual is effectively exact and never drifts.
Illustrative example. With SOFR at 4.31% and a $10,000 prepaid balance, you’d earn roughly $10,000 × 4.31% × (1 ÷ 360) ≈ $1.20 on the first day, then a hair more each following day as it compounds — about $440 over a year (≈4.40% APY) if the rate held steady. The actual figure moves with SOFR.
Eligibility<br>Section titled “Eligibility”
Every organization with a prepaid balance above zero earns interest automatically. There’s no opt-in, no minimum term, and no minimum balance beyond having prepaid credit on the books. Spend the balance down and accrual simply scales with whatever is left; top it up and the larger balance earns more the very next day.
Where to see it<br>Section titled “Where to see it”
Interest figures appear on the My Organization page (sidebar → Usage & Billing → My Organization ), alongside your trial/prepaid balance breakdown:
Interest earned to date — the lifetime total credited to this org.
Current rate and APY — the annual rate we’re paying right now and its daily-compounded effective yield.
The SOFR rate it’s based on , and the date that rate is effective for.
Auditability<br>Section titled “Auditability”
Every day’s accrual is recorded twice: as a durable ledger row (one per organization per day) and as a tamper-evident entry on the billing audit stream. Each record captures the principal it was computed on, the exact SOFR rate and its effective date, the applied annual rate, the day’s interest, and the resulting balance — so any single dollar of interest can be traced back to the published benchmark that produced it.