UK Mortgage Underwriting & Affordability
In testing
Decide mortgage applications end to end under MCOB 11, from stressed affordability to credit history and property policy, with a full rationale for every approve, refer or decline.
3 August 2026
- Verification Report
- Included
- Integration Guide
- Included
- Performance Report
- Included
- MCP endpoint
- Included
- Demo interface
- Included
- Demo Video
- Not included
The decision, and the evidence it returns
Every call returns the outcome, a certainty factor, a fact identifier and the full evidence tree: the rules that fired, the facts they used and the reasoning that joined them. Backward chaining means the reasoning engine only asks for the data it needs.
Rainbird accelerators produce precise, deterministic and fully auditable decisions without calling an LLM for judgement, and each one can be pivoted to your policy and integrated over API or MCP.
What's inside, and how it's proven
A decision in principle or a full application goes in, and the graph underwrites it end to end under MCOB 11: income reliability with per-category evidence rules, committed and essential expenditure, the stressed affordability test and its exemptions, credit event severity and recency, property and loan-to-value policy, deposit and source of funds, and lending into retirement. It returns exactly one of four decisions with named reasons, attached conditions, a customer explanation written for Consumer Duty and the audit rationale MCOB requires. Every threshold lives as a fact on the lending policy rather than inside a rule, so recalibration is a data edit, and missing data can never produce an approval, only a referral for the information that is missing.
What ships when available
This accelerator is in testing. Register interest and you get the whole pack on the day of release.
Rainbird Graph (.rbird)
For importing into your Rainbird account.
Documentation
Verification report and integration guide.
Performance Report
Query performance and per-scenario latency.
MCP endpoint
Connect this knowledge graph to agentic platforms over MCP.
Core Evals
The 26 pure inject-query-assert studio tests.
Adversarial Evals
Adversarial tests that stress the decision boundary.
Demo Interface
A demo interface to test the accelerator.
Demo Video
A demo video to explain the functionality.
This accelerator is open source under the MIT licence. It encodes public regulation, policy and research. You are free to download, inspect, adapt and redistribute the knowledge graph, its test suite and its documentation. Running it in production, with evidence trees, versioning and support, requires a Rainbird commercial licence.
Bring us the decision and we will build the graph
Contact us to discuss your decision use case.