https://www.dotnetzone.gr:443/cs/blogs/abekiaris/archive/2011/01/24/easy-sequential-numbers.aspxWhere they can be used?? In many places for example invoices, sales orders etc. One could tell that this is an easy task and maybe that assumption is right but let me write down some real world requirements that can prove the opposite to you. InvoiceselCommunityServer 2.1 SP3 (Build: 20423.1)