Is Certification is necessary for SAP functional consultant?

Hi All,

I have 6 years of experince in Siebel (4 years) & SAP CRM (2 Years) as a end user now I want to drive my career as SAP CRM consulatnt (Functional). so is SAP Certification is mandatory to get a job as SAP CRM Consulatant ? Is it very difficult to get a job as a consulatant after working as a end user for SAP CRM ? Please suggest for me .

Thank You,

Prafulla