RE: Posted sales invoices missing invoice
If you didn't delete it then it is still in the sales order list or sales invoice list.
What is that mean?
In NAV posting No. is assign to a invoice at the time posting. So what you saying is totally correct. Your posted sales invoice list should have the proper no series and it should not have any missing numbers.
However there is a one case this can be happen.
Think if you have posted your first invoice and it got the number 103118. Then you try to post your second invoice. So that NAV will assign a 103119 to your second invoice. Think this invoice gets a error at the time of posting. Then NAV will not reverse that assign No. and it will keep it as a posting No.
So since these is a error you skip the second one and post the third invoice. Nav will assign 103120 to your third invoice becasue NAV never reverse the no. series.
So what will happen to 103119 ? Nothing to worry about. When you correct that error and post it, It will post as the 103119 and you will not find any sequence error in your posting series.
As a solution check is there any invoice without posting. :)