There is nothing certain in this life but death and taxes!

The proverb contrasts life's many uncertainties with two outcomes it presents as unavoidable: death and the obligation to pay taxes. Its claim is deliberately sweeping rather than a precise statement about every person's circumstances.

It expresses skepticism toward confident predictions or promises. By naming two unwelcome certainties, it can also lend a dry, resigned humor to the observation that other plans may not work out.

Use it when someone treats an uncertain outcome as guaranteed, or when plans are disrupted by something unforeseen. Its reference to death makes it less suitable for a conversation in which a recent loss calls for sensitivity.