1. Reconciliation is a process of clearing/matching your 
Dr/Cr entries against the Bank statement.

2. Customer and vendor accounts are sub ledger GL's. We 
will have to create two reconciliation GLs in viz. 


While creating customer and vendor master records, we have 
to mention respective reconciliation GL in their company 
code segment details. This recon a/c will show you the net 
balances in GL for customer and vendor a/cs. 

Without creating Vendor you can still create individual GL 
for each customer and vendor , but then 
1) Your list of GL's in chart of account will be very 
lengthy. 
2) Duplication of work as SD/ MM people are also required 
to create their own list. 
3) Cross company code consolidation will not be possible as 
the chart of accounts will be different. 
4) Very difficult to keep track of individual customer/ 
vendor a/cs. 
5) Not advisable even in real time accounting system i.e. 
manual book keeping. 

Reconciliation a/cs( also called Control A/cs in pure 
accounting) are the net figures for items such as Drs and 
Crs of an organisation.  since it would not be possible to 
show the complete list of all vendors in the B/S, a recon 
a/c is maintained for the purpose.
however, the main feature of a recon a/c is that the debits 
MUST equal the credits in each entry, and so no mistakes in 
entries are possible (at least mathematically).  
Only if the organisation has a handful of suppliers and 
customers is it advised that no recon a/c is opened.

While posting data throw subledgers (like, 
customer/vendor/asset master records, it should be 
automaticlly updating in main GL A/c. That is the reason 
sap is useing reconcialation. 

Without reconcialatiion u can creat master record, but 
cannot post any entry in subleger.

Procedure: Create GL a/c in fsoo, control data 
reconcialation type has to be select.

when ur creating customer/vendor a/cgroup, field status 
make it required entry.