Be Late – When you are late, it shows a lack of respect for your work and your co-workers. While there are times that you cannot help it due to circumstances beyond your control, such as traffic, the alarm not going off or other reasons, there is no reason to be late just because you run out of time. If this happens to you often, then you need to change your routine to prevent it.
Use Slang or Internet Language – Depending on your business, you may feel that it is okay to use slang in your speech. This is not acceptable as not everyone will understand what you are saying. The slang may have a different meaning to someone else, and you could end up insulting them.
No E-mail Topic/Generic Topic – When sending an e-mail, you should always input a topic that is relevant to what you are sending. This way the receiver is able to know at a glance how important it is and they can determine how quickly they must deal with it.
Interrupt – There is nothing ruder than interrupting someone else, especially if they are discussing a work problem. If you want to suggest something, or if you need to speak to the person immediately, it is best to wait your turn or gently say “excuse me" when there is a break in the conversation.
Dress Sloppy – You should always do your best to make a good impression. Being sloppy makes it appear that you do not care about your job or those around you. You never know when you may be passed over for promotion or other incentives because the company does not feel you would do a good job representing it with the way you look.
There are many other things that fall on the list of business do-and-don’ts, but this is a good start if you need some typical office guidelines.