# Billing & credits
Workspaces are prepaid: you top up a credit balance, each request draws it down, and at zero the
API returns a `402`. There is no overage billing.
## Topping up
Top-ups are by card, $5 to $5,000, with a processing fee of 2.9% + $0.30 itemized at checkout.
The fee never comes out of your balance. All payments are secured by Stripe: Stripe handles the
payment details, and Keln never stores them. The card stays on file (one per workspace) for
one-click top-ups and auto top-up.
<a id="auto-recharge"></a>
## Auto top-up
Set a threshold and an amount on the Billing page. When the balance falls below the threshold,
Keln charges the amount to the saved card. It does not charge again until the previous charge has
credited, and emails you if a charge is declined.
## Invoices and receipts
Keln emails a numbered receipt (`TOP-YYYY-NNNN`) for every top-up, and an invoice PDF is
available per payment once you fill in your [billing details](#billing-details). Keln also emails
you when the balance drops to $5, when it runs out, and when an auto top-up fails.
## Billing details
Your name and address, and for a business its tax ID. Keln generates invoices from these details.
## Who can change billing
Only the workspace owner can change billing: top-ups, the card, auto top-up, and billing details.
Admins can view the page but not edit it ([Teams](teams.md)).
## The fine print
Credits pay for Keln usage only and never expire. Prepaid credit is non-refundable except where
the law requires it. A request that fails on Keln's side bills nothing; a generation you cancel bills
what was delivered. The [Terms of Use](https://keln.ai/terms) govern credits. Keln adds no tax at checkout.
Billing & credits
Workspaces are prepaid: you top up a credit balance, each request draws it down, and at zero the
API returns a 402. There is no overage billing.
Topping up
Top-ups are by card, $5 to $5,000, with a processing fee of 2.9% + $0.30 itemized at checkout.
The fee never comes out of your balance. All payments are secured by Stripe: Stripe handles the
payment details, and Keln never stores them. The card stays on file (one per workspace) for
one-click top-ups and auto top-up.
Auto top-up
Set a threshold and an amount on the Billing page. When the balance falls below the threshold,
Keln charges the amount to the saved card. It does not charge again until the previous charge has
credited, and emails you if a charge is declined.
Invoices and receipts
Keln emails a numbered receipt (TOP-YYYY-NNNN) for every top-up, and an invoice PDF is
available per payment once you fill in your billing details. Keln also emails
you when the balance drops to $5, when it runs out, and when an auto top-up fails.
Billing details
Your name and address, and for a business its tax ID. Keln generates invoices from these details.
Who can change billing
Only the workspace owner can change billing: top-ups, the card, auto top-up, and billing details.
Admins can view the page but not edit it (Teams).
The fine print
Credits pay for Keln usage only and never expire. Prepaid credit is non-refundable except where
the law requires it. A request that fails on Keln's side bills nothing; a generation you cancel bills
what was delivered. The Terms of Use govern credits. Keln adds no tax at checkout.