1.I want to sincerely apologise for the oversight on my part. I take full responsibility and I'm already working to put it right.

2.Please accept my apologies for the delay. It wasn't up to my usual standard, and I'll make sure it doesn't happen again.

3.I'm sorry for the miscommunication earlier. I value our working relationship and want to make sure we're aligned going forward.

4.Thank you for your patience. I apologise for the inconvenience this caused, and I appreciate you giving me the chance to fix it.

5.I realise my error affected your work, and I'm truly sorry. I've corrected it and put steps in place to prevent a repeat.