Two tables with same field
This is definitely a case where you should use one table IMHO.

The entities involved are virtually identical only differing by 1 important field - that makes them very good candidates for a single table.

Have the SOA_account_number in the table and set it to NULL if the quote hasn't been approved and have a value set when the approval process has been successfully completed.

This simplifies your schema and all you have to do to distinguish between pending and approved quotes is to use a WHERE clause - i.e. 

WHERE SOA_account_number IS (or IS NOT) NULL


You haven't given us the full table structure (SHOW CREATE TABLE My_Table\G), but I would suggest having a couple of DATE fields (or possibly DATETIME) - something like quote_offered_date and quote_accepted_date. Just a couple of thoughts.