Tell the truth about where the morning breaks, use one task-based alarm away from bed, and keep a separate backup. If you're still sleeping through everything, get help instead of trying to outshout the problem.
This is scary, and pretending it isn't won't help
You have already heard the warning from your manager, or you can feel it coming. Every night now carries the same thought: what if I do it again? That fear can lead to twelve alarms, an hour of broken sleep, and a morning that is somehow even less dependable. Take a breath. We can make the next attempt more concrete.
Write down what happened on the last three late mornings. Did the sound never register? Did you turn it off with no memory? Did you get up and return to bed? Did you wake on time but lose forty minutes before leaving? A new ringtone only helps with the first of those, and even then it may not be enough.
Build one wake-up you can actually test
Give yourself a realistic time in bed. Put the main alarm task in the bathroom or beside your work clothes, and keep one backup on a different device or power source. Prepare keys, clothes, food, and transport. Test every part while awake so the important morning isn't also the first trial.
If this keeps happening despite enough time for sleep, or you snore loudly, gasp, wake with headaches, or fight sleep during the day, please see a healthcare professional. Riso can stop a half-awake thumb from ending the alarm too easily. It can't diagnose the reason waking is so hard, and your job shouldn't have to be the price of finding out.
Common questions
Should I tell my manager I have an alarm problem?
You can keep health details private while being honest that you are addressing repeated lateness. Follow workplace policy and ask about any support that applies.
Would putting my phone across the room be enough?
It may help if reaching from bed is the problem. If you walk over and return, put the task somewhere that begins getting ready and add a later check.
Sources & further reading
We use primary public-health guidance and original research where the topic makes factual claims about sleep. Sources are reviewed for relevance, not used as decoration.