# Set the amount: fixed, custom, products, per person, coupons and fees

> Every way a Payment field can decide what to charge, plus discount codes and passing your processing fee to the payer.

**How much to charge** on a Payment field has six modes: **Fixed**, **Custom** (the payer types an amount), **Multiple** (they pick one option), **Products** (they pick several with quantities), **Per person or item** (a quantity times a price), and **Per seat** (one price for every seat booked on the form's Appointment Booking field; the customer chooses how many seats there, see [Sell tickets per time slot](/services/sell-tickets-per-time-slot)). Coupons and an optional fee apply on top.

![The How much to charge menu open, listing Fixed, Custom, Multiple, Products, Per person or item, and Per seat with a description under each](/docs-assets/payments/payment-amounts-coupons-and-fees-1.png)

## Charge a single fixed amount

1. Open **Advanced edit** for your **Payment** field.
2. Under **How much to charge**, choose **Fixed**.
3. Under **Fixed price**, enter the **Amount**.

## Let the payer type their own amount

Choose **Custom** to let the payer enter any amount themselves, useful for donations or pay-what-you-want pricing. There's no amount to set here: the field has nothing to configure beyond the **Payment description** shown above the payer's amount box.

## Offer a few preset prices

Choose **Multiple** to let the payer pick one option from a list you define. Under **Price options**, give each row a **Label** and an **Amount**, and select **Add option** to add more.

## Sell products with quantities

Choose **Products** to let the payer order several items by quantity, like a small storefront on the field. Under **Products**, give each row a **Label** and an **Amount**, and optionally limit it with **Min qty** and **Max qty**. Select **Add option** to add more items.

![The Products section with two rows, T-shirt at 20 USD and Mug at 12 USD, each with Min qty and Max qty columns](/docs-assets/payments/payment-amounts-coupons-and-fees-2.png)

## Charge per person or item

Choose **Per person or item** to charge the same amount for each one the payer adds, then collect details for each. Under **Per-unit price**, set the **Amount per unit**, the **Name for each one** (the noun payers see, such as "Person" or "Ticket"), and optionally a **Maximum per submission**. Under **Details collected for each one**, add the fields the payer fills in for every one they include.

## Add a discount code

1. Under **Coupons**, select **Add coupon**.
2. Enter the **Code** the payer will type in.
3. Choose a **Discount type**: **Percentage**, **Fixed**, or **Free**.
4. For **Percentage** or **Fixed**, enter the **Value**. **Free** has no value to set: it discounts the full amount.

A code matches regardless of capitalization or extra spaces around it, so `SAVE10`, `save10`, and ` save10 ` all apply the same coupon.

If Maxforms has enabled Services for your workspace and this field bills on a recurring schedule, **Free** isn't offered as a discount type, since a 100% discount would create a subscription that charges nothing.

![The Coupons section with a coupon code SAVE10 set to a 10 percent Percentage discount](/docs-assets/payments/payment-amounts-coupons-and-fees-3.png)

On the published form, the payer selects **Add discount code** to reveal the code box.

## Pass your processing fee to the payer

1. Under **Fees**, turn on **Enable fee**.
2. Select **Add Fee**.
3. Give the fee a **Label** (what the payer sees on checkout), a **Type** (**Percentage** or **Fixed**), and an **Amount**.
4. Leave **Show fee label to user** on to break the fee out as its own line on checkout, or turn it off to fold it into the total silently.

## If the total is wrong, then check quantities and the coupon

1. On **Products** or **Per person or item**, confirm the quantities the payer entered match what you expected; the total is quantity times price per row.
2. If the payer sees **Invalid discount code.** under the code box, compare it against the exact **Code** you set: matching ignores case and spaces, so a message that stays after correcting those means the payer typed a genuinely different code. The code is checked again at submit, so it can't slip through misspelled.
3. A **Percentage** coupon set to 100% discounts the price to zero but leaves an enabled fee in place. Only a **Free** coupon zeroes both the price and the fee.