This document summarizes key considerations for collaborative working agreements and trading subsidiaries between charities. It outlines the legal structures available, including contractual collaboration and forming a new legal entity. When collaborating, charities should understand objectives, culture, and limitations. Choosing the right partners requires addressing politics, policies, and exit strategies. Contractual agreements must define responsibilities, timelines, governance, cost/liability sharing, and dispute resolution. Trading subsidiaries can ring-fence risk but require agreements on activities, asset use, record keeping, profit distribution, and termination.