# Customers
A comprehensive tool is available for system administrators to manage the customers:
* Data of customers
* Users of customers
* Invoices of customers
* Plans of customers
* Modules of customers
## Data of customers
Click the Edit button to edit the customer's data:
For more details, click the company name:
## Users of customers
When you opened the details of a company, click the register `Users` to view and edit a user:
You can only edit the salutation, first name, surname and email address.
{% hint style="info" %}
Changing an email address does not trigger a confirmation email. Users may not be able to log in if they are not aware of the change of address.
{% endhint %}
## Invoices of customers
Click the register `Invoices` to view and edit an invoice:
You have more options by clicking to the button `Action`:
* Add a new invoice for this customer
* Edit an existing invoice
* Print an existing invoice
* Send the invoice to the customer by e-mail
* Delete an existing invoice
## Plans of customers
Click the register `plans` to view and edit the customer’s plan:
In this tab you have the option to book, downgrade or upgrade a plan for the corresponding customer. Each available plan is displayed in a box. The button `Action` contains various options depending on the status of the plan:
#### **Activate now (free)**
The plan is activated immediately without charging an amount
#### **Activate the test time (xx days)**
Activate the plan with test time. Depending on how many test days you have given to the plan, the client can test for as long as they want.
#### **Make invoice for monthly cycle ($ xx)**
You can create an invoice for the customer first, which he then must pay. Only after the invoice is defined as "paid" the plan is activated.
#### **Make invoice for yearly cycle ($ xx)**
You can create an invoice for the customer first, which he then must pay. Only after the invoice is defined as "paid" the plan is activated.
#### **Edit period**
In the case of a plan that has already been booked, it is possible to change the term/period.
#### **Cancel at expiry date**
Cancel the booked plan at the expiry date.
#### **Withdraw plan**
Withdraw and delete the plan. Any credit balance will not be reimbursed and will also be deleted.
## Modules of customers
Click the register `modules` to view and edit the customer’s modules:
In contrast to the plans, the client may have activated several modules. Here you can manage the modules.
#### **Activate now (free)**
The module is activated immediately without charging an amount
#### **Activate the test time (xx days)**
Activate the module with test time. Depending on how many test days you have given to the module, the customer can test for as long as they want.
#### **Make invoice for monthly cycle ($ xx)**
You can create an invoice for the customer first, which he then must pay. Only after the invoice is defined as "paid" the module is activated.
#### **Make invoice for yearly cycle ($ xx)**
You can create an invoice for the customer first, which he then must pay. Only after the invoice is defined as "paid" the module is activated.
#### **Edit period**
In the case of a module that has already been booked, it is possible to change the term/period.
#### **Cancel at expiry date**
Cancel the booked module at the expiry date.
#### **Withdraw plan**
Withdraw and delete the module. Any credit balance will not be reimbursed and will also be deleted.
