ProofWorks Limited
Sub-processors
Last updated: 4 May 2026
To deliver the BidEngine platform, ProofWorks Limited engages a small number of carefully-selected third-party services (“sub-processors”). This page sets out the categories we use, their data locations, and the safeguards in place.
The detailed list of named sub-processors, with the specific vendor in each category and a copy of our Data Processing Agreement, is available to customers and qualified prospects on request — email privacy@bidengine.co.
Categories of sub-processor
| Category | Purpose | Data location | Transfer mechanism |
|---|---|---|---|
| Primary database | Stores customer evidence library, tender data, account records, and audit logs | UK only | UK only — no transfer |
| Application hosting | Hosts the platform and runs serverless functions; primary processing in the UK | Primary region: London (LHR) | UK IDTA where the parent vendor is non-UK |
| Large language models | Generation, scoring, and improvement of tender responses; embedding for semantic search | United States | UK IDTA. Customer data is not used for model training under our agreements. |
| Authentication | User sign-up, sign-in, session management, multi-factor authentication | United States | UK IDTA |
| Payment processing | Subscription billing | UK contracting entity, with limited US processing under the UK’s adequacy framework | UK IDTA where applicable |
What our sub-processors see — and don’t see
- Per-tenant isolation: each customer’s evidence library is logically isolated and is never used in another customer’s drafts.
- AI providers see only the specific content needed for an inference call — the question being answered and the relevant evidence records selected by our retrieval layer for that question. They do not see your full evidence library.
- Authentication and payment providers see identity and billing data only. They do not see your evidence library or tender data.
- No advertising networks and no third-party marketing trackers operate on the application.
Sub-processor changes
If we add a new sub-processor that processes personal data, we will notify active customers by email at least 30 days in advance. Customers may object to a new sub-processor on reasonable data protection grounds during the notice period; if we cannot accommodate the objection, the customer may terminate the affected service.
How to obtain the detailed list
The named sub-processor list is a commercially-sensitive document that we share with customers and with qualified prospects in active evaluation. To request a copy, email privacy@bidengine.co from a corporate domain. We will share the list together with our Data Processing Agreement, typically within one working day.
Public sector procurement teams: we are familiar with standard ITT data protection schedules and will respond to formal data protection questionnaires (e.g. CCN, GCloud, supplier security assessments) on the same email address.