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 comes down to who owns the decision, not politeness. 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.
Sometimes the right move isn't informing or asking your manager at all, it's going above them. That's allowed. The method is what makes or breaks it.
Tell your manager first. That is what preserves the trust, before you ever raise something with their boss.
"I want to be straightforward with you, I'm planning to raise the budget concern directly with Sarah, since it's ultimately her call and I don't think it's something you can resolve on your own. Wanted you to hear that from me first, not find out after."
Going around your manager rarely damages the relationship. Going around them without telling them almost always does.
That message doesn't ask permission, and it doesn't need to. It just removes the surprise, which is usually what actually breaks trust, more than the escalation itself. The one exception: if the concern is about your manager's own conduct, skip the heads-up and go straight to HR or their boss.
Both situations come down to the same habit. Decide plainly what you actually mean, inform, ask, or escalate, and say that one thing clearly instead of a soft message that leaves someone guessing.