If it turns out there has been a mistake or miscommunication about who a certain job is for, you can adjust it in two different ways - either by editing the customer or changing the customer that the job is for:
Editing the customer
You can edit the customer by clicking the ✏ pencil icon next to their details on the job card > Job Summary. This will open the edit screen where you can make adjustments to their information. Editing this info will affect all existing jobs for this customer.
Changing the customer
The other option is to change to a different customer by selecting the ❌cross. This allows you to search for someone else in your customer list to assign the job to.
You'll see both these options on the Main Contact and Site Contact too.