In Magento, customers don’t use special numbering by default; however it is possible to change this. We need to add a record to the
eav_entity_store table with
entity_type_id = 1,
increment_prefix = CU and
increment_last_id = CU001000.
In Magento, order numbers are generated starting from
100000001 and up by default. Many companies want to use a custom value so that customers don’t know exactly how many orders have been placed before. Others need a custom value to match other parts of their system. The field
increment_id is present in various entity tables to store this number.