HMRC and Payroll Systems Hit by Major Amazon Outage — How We’re Ensuring Data Integrity

A major global technology outage on Monday morning caused widespread disruption to HMRC systems and multiple UK payroll software platforms. The issue, linked to Amazon Web Services (AWS) infrastructure problems, left businesses across the country temporarily unable to process payroll, access employee records, or submit tax data.

While the incident was outside any provider’s control, the impact was immediate; real-time connections to HMRC were down, tax code updates could not be retrieved, and payroll systems relying on Amazon AWS cloud access were inaccessible.

At Crystal HR & Payroll, our response was immediate and focused on one principle:

Protecting the accuracy and integrity of every client’s payroll data.

1. Protecting data before anything else

As soon as we confirmed system failures due to Amazon Outage, we paused all live payroll processing to avoid any risk of corrupted or incomplete data.
Our team then began a structured verification and recovery plan, ensuring that when systems came back online, we could restart operations safely and confidently.

2. Comprehensive post-outage payroll data checks

Once access was restored and the Amazon Outage was fixed, we launched a detailed data integrity review across all affected systems. This included:

• HMRC Gateway verification: confirming coding notices (P6, P9, SL1, SL2) are being correctly downloaded into payroll software with a live check of the HMRC Gateway messaging and coding notices section.
• Tax code and loan validation: cross-checking employee tax codes, student loan and postgraduate loan notices, and any National Insurance category updates.
• Paper notice tracking: contacting clients to ask if any employees received paper communications from HMRC within the last month to forward a copy to us, ensuring all manual updates are cross checked against HMRC systems.
• Software reconciliation: comparing pre-outage backups with current payroll data to confirm totals match and no records were duplicated or rolled back.
• Client funding confirmation: checking that clients who manage their own payments can still access and process via Modulr, BACS or other platforms before payroll completion.

“When systems recover, you can’t just pick up where you left off,” says Sarah Carter, Managing Director.
“Every figure, tax code, and deduction has to be verified. We treat data integrity as the backbone of payroll, especially after an event like this.”

3. Communicating with clients

We’ve been in direct contact with clients throughout the day, providing updates and requesting verification of any recent HMRC paperwork or coding notices received by staff.
This collaboration ensures any missed digital updates can be captured manually, keeping payroll accurate and compliant despite the disruption.

4. What businesses can learn

Outages like this underline how dependent payroll operations have become on third-party systems and integrations. While such incidents are rare, they’re a reminder that resilience and verification processes are just as important as speed and automation.

We’re now reviewing additional contingency options, including:

• Secondary payroll backups for emergency access.
• Secondary data verification routines.
• Clearer client communication channels for any future service interruptions.

5. Back online and back to business

With systems now fully restored, payroll processing has resumed and all data integrity checks have been completed.
We’ll continue to monitor system stability and maintain audit logs of every step taken during the outage response.

“Our clients trust us because we act quickly,” says Sarah.
“We don’t guess, we verify and that’s what ensures payroll accuracy, even when the unexpected happens.”

Crystal HR & Payroll continues to operate as normal following the outage.
If you have questions about your payroll data or need assistance reviewing your employee records, please contact your dedicated payroll specialist.

📎 Reference: AWS Service Health Dashboard

Outages happen. Inaccurate payroll shouldn’t.
If you’d like to understand how your payroll system can stay compliant and resilient during future disruptions, get in touch for a no obligation chat.