Here is the issuing authority that issues ews certificate that is valid everywhere:

INCOME AND ASSET CERTIFICATE ISSUING AUTHORITY AND VERIFICATION OF CERTIFICATE:

The benefit of reservation under EWS can be availed upon production of an Income and Asset Certificate issued by a Competent Authority. The Income and Asset Certificate issued 'by any one of the following authorities in the prescribed format as given in Annexure-I shall only be accepted as proof of candidate's claim as 'belonging to EWS: -

(i) District Magistrate/Additional District Magistrate/ Collector/ Deputy Commissioner/Additional' Deputy Commissioner/ 1st Class Stipendary Magistrate/ Sub-Divisional Magistrate/ Taluka Magistrate! Executive Magistrate/ Extra Assistant Commissioner

(ii) Chief Presidency Magistrate/Additional Chief Presidency Magistrate/ Presidency Magistrate

(iii) Revenue Officer not below the rank of Tehsildar and

(iv) Sub-Divisional Officer or the area where the candidate and/or his family normally resides. 5.2 The Officer who issues the certificate would do the same after carefully verifying all relevant documents following due process as prescribed by the respective State/UT. 5.3 The crucial date for submitting income and asset certificate by the candidate may be treated as the closing date for receipt of application for the post, except in cases where crucial date is fixed otherwise.

5.4 The appointing authorities should, in the offer of appointment to the candidates claiming to be belonging to EWS, include the following clause :-

"The appointment is provisional and is subject to the Income and asset certWcate being verified through the proper channels and if the verffication reveals that the claim to belong to EWS is fake/false the services will be terminated forthwith without assigning any further reasons and without prejudice to such further action as may be taken under the provisions of the Indian Penal Code for production offake/false certificate."

The appointing authority should verify the veracity of the Income and asset certificate submitted by the candidate through the certificate issuing authority

5.5 Instructions referred to above should be strictly followed so that it may not be possible for an unscrupulous person to secure employment on the basis of a false claim and if any person gets an appointment on the basis of such false claim, her/his services shall be terminated invoking the conditions contained in the offer of appointment

Hello candidate,

YES, you can use your EWS certificate issued under the state government for all type of national level exams. It is well valid all over the country.

Hope it helps.

Thank you!!!