Decomposition is favoured by increasing temperature, and disfavoured by the presence of fluorine gas, but the exact parameters of the equilibrium are unclear, with some sources saying that MnF4 will decompose slowly at room temperature, others placing a practical lower temperature limit of 70 °C, and another claiming that MnF4 is essentially stable up to 320 °C.
The process of decomposition is promoted by higher temperatures, while the presence of fluorine gas discourages it. However, the exact conditions required for equilibrium are not well-defined, with varying accounts suggesting that MnF4 decomposes slowly at room temperature, has a practical lower temperature threshold of 70 °C, or remains stable up to 320 °C.