# Add discounts, upsells, and optional items

Boost sales with discounts and offers.

[Add discounts](https://docs.stripe.com/payments/checkout/discounts.md): Reduce the amount charged to a customer by discounting their subtotal with coupons and promotion codes.

[Configure free trials](https://docs.stripe.com/payments/checkout/free-trials.md): Offer customer free trials on subscriptions.

[Configure subscription upsells](https://docs.stripe.com/payments/checkout/upsells.md): Enable customers to upgrade their subscription plan at checkout by using upsells.

[Add optional items](https://docs.stripe.com/payments/checkout/optional-items.md): Enable customers to purchase complementary products at checkout by using optional items.

[Let customers complete orders for free](https://docs.stripe.com/payments/checkout/no-cost-orders.md): Accept orders for no-cost line items, and apply 100% off discounts in payment mode.