There is a small charge of 0.07p per SMS sent to your customer. You will be charged for each SMS you send via Stripe.
An invoice for your usage each week (SMSs sent Monday - Sunday) will be created on Sunday. The invoices will then be paid from the online payments you receive from your clients to avoid any further transaction charges.
To view a breakdown of your SMS costs, visit 'Message invoices' in the Payments section of your app.