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.
Decomposition is favored by rising temperatures and hindered by the presence of fluorine gas, yet the exact parameters governing this process are uncertain, with varying accounts suggesting that MnF4 decomposes slowly at room temperature or remains stable up to 320 °C.