28b3984c_mal_and_Informal_Communication__Informal_communication
[SL] 7 [Points of Difference] Errors or Mistakes [Formal communication] Very careful attention is given here in encoding the message and sending the message through formal way. Due to this seriousness, there is less chance of mistakes or errors. [Informal communication] 
It is personal in nature and therefore less attention is involved which can cause many errors or mistakes.
Difference Between Formal and Informal Communication
Informal communication