Assignment (law)
When assignment will be permitted

Unless otherwise agreed all rights of either seller or buyer can be assigned except where the assignment would materially change the duty of the other party, or increase materially the burden or risk imposed on him by his contract, or impair materially his chance of obtaining return performance. A right to damages for breach of the whole contract or a right arising out of the assignor's due performance of his entire obligation can be assigned despite agreementotherwise.
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