Uncontrollable costs (also known as irrelevant costs) are costs that cannot be influenced by certain decision.
These are usually costs where is the entity obliged to pay fixed costs based on the contract - for example rent or telephone charges.
It does not make any sense to consider these costs during decision-making between different alternatives, because they remain unchanged in any case.
Certain type of uncontrollable costs are sunk costs.
Opposite to uncontrollable costs are controllable (relevant) costs.