Excel Sequential Numbering System

[lee1979]

I'm trying to find out if there is a formula or macro that will help me create a sequential numbering system for inventory across multiple tabs or worksheets. I need it to maintain the last number generated and when I enter a new item to any of the worksheets it automatically generates a new number for this item base on the last issued number. The formula I am using right now allows me to somewhat do what I want but I have to remember the last number and change the formula accordingly so it maintains the numbering sequence plus I have to copy this formula to each line item. This is my formula I am using right now of =TEXT(ROW(A2),"000-000").