Buy Now, Pay Later Methods: Klarna, Afterpay, and More

Buy now, pay later (BNPL) methods let shoppers split or defer the cost of a purchase — paying in installments over weeks or months, or settling the full amount after a deferred period. Therius routes all BNPL methods through the same POST /payment/purchase endpoint with no extra integration work. Each method returns a redirect URL in actionRequired.url for the shopper to complete their BNPL application with the provider.

Pass apm.lineItems with product names, SKUs, quantities, and unit prices whenever possible. BNPL providers use line item data for credit scoring, and including it typically improves approval rates.

BNPL order limits vary by provider and market. Klarna and Afterpay may decline orders below or above certain thresholds — check the provider’s current documentation for minimum and maximum order values in your target market.

Klarna — `klarna`

Klarna offers three payment options in a single integration: pay later (30 days), pay in installments (3–36 months), and pay now. Klarna determines which options to show the shopper based on their account and order details. Supported currencies: USD, EUR, GBP, SEK, NOK, DKK, PLN, and more.

{
  "merchantCode": "MERCHANT_001",
  "orderCode": "ORDER-001",
  "amount": { "currency": "USD", "value": 5000, "exponent": 2 },
  "paymentMethod": "klarna",
  "apm": {
    "method": "klarna",
    "returnUrl": "https://yourshop.com/payment/return",
    "cancelUrl": "https://yourshop.com/payment/cancel"
  }
}

Afterpay / Clearpay — `afterpay_clearpay`

Afterpay (known as Clearpay in the UK) splits the order into four equal fortnightly installments at no interest. Supported currencies: USD, GBP, AUD, NZD, CAD.

{
  "merchantCode": "MERCHANT_001",
  "orderCode": "ORDER-001",
  "amount": { "currency": "USD", "value": 5000, "exponent": 2 },
  "paymentMethod": "afterpay_clearpay"
}

Affirm — `affirm`

Affirm offers flexible monthly installment plans ranging from 3 to 36 months. It is available in the United States and Canada. Supported currencies: USD, CAD.

{
  "merchantCode": "MERCHANT_001",
  "orderCode": "ORDER-001",
  "amount": { "currency": "USD", "value": 5000, "exponent": 2 },
  "paymentMethod": "affirm"
}

Zip — `zip`

Zip (formerly Quadpay in the US) splits purchases into four installments paid over six weeks. Available in Australia, New Zealand, and the United States. Supported currencies: AUD, NZD, USD.

{
  "merchantCode": "MERCHANT_001",
  "orderCode": "ORDER-001",
  "amount": { "currency": "AUD", "value": 5000, "exponent": 2 },
  "paymentMethod": "zip"
}

​Klarna — klarna

​Afterpay / Clearpay — afterpay_clearpay

​Affirm — affirm

​Zip — zip

Klarna — `klarna`

Afterpay / Clearpay — `afterpay_clearpay`

Affirm — `affirm`

Zip — `zip`