Tax indemnity
The best kind of indemnity. One of the few occasions where contractual indemnity is generally justified and reasonable — if an unexpected tax is imposed on one party in respect of its activity in providing a service (holding its assets in custody for example) for the other. It ticks all the boxes of a good indemnity: It is precise, specific and easy to articulate; it is hard to predict or cost into one’s service, it is deterministic in amount, and doesn’t open up the indemnifying person to indeterminate liability.