Confusing the two costs you in both directions, asking permission for something that was actually just your call makes you look unsure of your own authority, and informing someone of something that actually needed their sign-off can blow up a relationship fast.
The confusion usually comes from softening language that's meant to sound polite but ends up ambiguous about what's actually being asked. "Just wanted to let you know I'm planning to move the deadline, let me know if that's an issue" reads as an FYI to some people and a request for approval to others, and if your boss reads it as an FYI while you meant it as a request for approval, you may proceed on an assumption that was never actually confirmed.
"Heads up, I'm moving our team's internal check-in from Tuesdays to Wednesdays starting next week, since it was conflicting with another recurring meeting. Nothing needed from you, just wanted you aware."
"I'd like to move our external deadline with the client from Friday to the following Tuesday. Can I get your go-ahead before I communicate that to them?"
The difference isn't just politeness, it's about who owns the decision. An internal meeting time is usually yours to decide and communicate. A client-facing deadline usually isn't, unless you've been explicitly given that authority. Sending both as soft, ambiguous "just wanted to let you know" messages blurs a distinction that actually matters.
If you're not sure whether something is your call, that uncertainty itself is the answer: ask.
A useful habit: before sending an update, decide plainly which category it falls into, and let the language reflect that clearly. If it's genuinely your decision, say so with confidence, "I've decided to move the check-in" rather than a hedge that invites a debate you didn't intend to open. If it needs approval, ask directly, "can I get your sign-off", rather than a soft FYI that leaves the actual decision ambiguous.
Getting this wrong in the direction of over-asking has its own cost too. A manager who asks permission for every small decision that was actually theirs to make signals they're not ready for more autonomy, even when their judgment is fine, the hesitation itself becomes the signal, regardless of the actual quality of their decisions.