Dear Customers,

As you know, on Monday 20th October 2025 at 8.11am (UK time) AWS (Amazon Web Services) reported an outage that affected systems around the world. This platform supports some of our Dentally services, and the outage impacted our support chat/phone, two-factor authentication, Concierge access and SMS.

AWS advised that their services were slowly recovering through the course of the day, and then confirmed they were operational and online at 11.53pm on Monday 20th October 2025.

Our team has been working throughout the incident, including through the night, to ensure that Dentally is fully operational. As part of our investigation we identified that some SMS messages had failed to send during the outage. These included:

• task reminders
• medical history requests
• appointment cancellation confirmations
• booking confirmations

To minimise the impact of these failed messages on your practice admin, our team have been able to send them today (Tuesday 21st October 2025). Please note: we have removed any messages that are no longer relevant.

It has been confirmed by AWS that the incident was caused by a DNS issue following a technical update to a core database service.  We are continuing to work closely with the AWS team to ensure clear resolutions are made to reduce the likelihood of this happening in the future.

We know that you will be disappointed to hear of this incident that occurred through our third-party supplier, and we apologise for the impact this may have had on your practice.

As ever, our mission is to support you in delivering exceptional patient care. Thank you for your continued support.

James Harker,

Executive Director, Henry Schein One, UK and APAC