> For the complete documentation index, see [llms.txt](https://docs.tipo.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tipo.io/tipo-appointment-booking/service-setup/set-add-on-charge-rules.md).
# Set Add-on Charge Rules
For multi-day services, you can choose how an Add-on is charged based on the **booking duration**, **number of participants**, or both.
This gives you more flexibility when offering extras such as equipment rental, meals, additional services, or other optional products.
For example, an equipment rental can be charged **per participant, per day**, while another Add-on can be charged only **once for the entire booking**.
***
### ⚙️ Set up an Add-on charge rule
1. Open the app > go to **Services** > open the multi-day service you want to edit
2. Scroll down to **Questions & Add-ons**
3. Click **Add questions** to create an Add-on field, or edit an existing Add-on
***
4. In the Add-on settings, find **How customers will be charged?** > choose the charging rule that best matches how you want to price the Add-on
You can choose from:
* **Per participant, per day**
* **One-time**
* **Per participant**
* **Per day**
5. Save the service to update the change
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### 💰 Understand each charge rule
Let's use the same example to see how each option works.
#### Example setup
Service: **Studio rent**
Booking duration: **3 days**
Participants: **2**
Add-on: **Lighting equipment**
Add-on price: **$20**
***
#### Per participant, per day
The Add-on is charged for each participant for each day of the booking.
With our example:
`$20 × 2 participants × 3 days = $120`
The Add-on total is **$120**.
This option is useful when the Add-on cost depends on both the number of people and the booking duration.
***
#### One-time
The Add-on is charged once for the entire booking, regardless of the booking duration or number of participants.
With our example:
`$20 = $20`
The Add-on total is **$20**.
Even though the booking is for 3 days and 2 participants, the Add-on is only charged once.
***
#### Per participant
The Add-on is charged once for each participant, regardless of how long the booking lasts.
With our example:
`$20 × 2 participants = $40`
The Add-on total is **$40**.
The 3-day booking duration does not increase the Add-on price.
**Example uses:**
* Registration fee per person
* Equipment assigned to each participant for the whole booking
* Welcome package for each guest
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#### Per day
The Add-on is charged once for each day of the booking, regardless of the number of participants.
With our example:
`$20 × 3 days = $60`
The Add-on total is **$60**.
The number of participants does not affect the Add-on price.
***
| Charge rule | Calculation | Add-on total |
| ------------------------ | ----------- | ------------ |
| Per participant, per day | $20 × 2 × 3 | **$120** |
| One-time | $20 × 1 | **$20** |
| Per participant | $20 × 2 | **$40** |
| Per day | $20 × 3 | **$60** |
