Hi,

I would like to the pass the account information to external system whenever user insert/Update Account record in salesforce but the issue is i can't override New/Edit buttons because Account object is using other applications with different record types.

Please find the my design analysis
1)   Create "Sync Account" Java Script detail page button to Sync account data with external systems.  
            Issues     
              i) May user get an error while clicking "Syn Account" button from external system but Account data is already saved in salesforce.
              ii) User need to click button multiple times, to save Account record in salesforce and to sync account data with external system.
             iii)  May user forgot to click on Sync account button hence data is not sync with external system. 
2)   Creating an inline Vf page and invoking an external system on page load               
           Issues       
             i)   I think salesforce is not recommending this approach. 
3)  Invoking the external system using trigger handler class based on the record typeIssues:
        Issues            
            i)   Need to do check can we show the error messages on standard detail page from apex class. 
4)  Create a new Vf page to select the record type. Based on the selection of record type navigate to standard page or vf page.For current application navigate to new vf page which need to be created to invok an external system.
For other applications navigate to Standard detail page.
        Issues:
              i)    Development effort will increase because we need to create two vf pages. One for Selection of record type and next for invoking an                       external application to send account data.
              ii)    Existing validation rules should implement using flow or apex class.

Please let me know is there any other best possible solution. 
Thanks for your help in advance.