UK-US Double Taxation Resolver
In testing
Resolve UK-US double taxation positions, from residence and treaty tie-breakers to foreign tax credit ordering, with a rationale a dual-qualified adviser could review.
29 July 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
Four rulebooks interact, and the interaction is the whole problem: UK domestic law, US domestic law, the 2001 Convention and the social security agreement. The graph resolves residence under both domestic codes, applies the treaty tie-breakers and the saving clause with its exceptions, works each income item through its article, orders foreign tax credits and handles the FIG regime interaction, producing an adviser working position with a citation for every step. Its boundary is enforced by the vocabulary rather than a disclaimer: it never emits a filing instruction and never recommends an election, because sign-off is reserved to the adviser.
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
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.