Is possession of a Permanent Account Number (PAN) mandatory for obtaining a Registration

Yes. Every person should have a Permanent Account Number issued under the Income Tax Act, 1961 in order to be eligible for grant of registration under Section 25 of the CGST Act. Provided that a person required to deduct tax under section 51 may have, in lieu of a Permanent Account Number, a Tax Deduction and Collection Account Number issued under the said Act in order to be eligible for grant of registration. However, as per section 25 (7) the CGST Act, PAN is not mandatory for a non-resident taxable person for obtaining registration.

(ICAI FAQ PUBLICATIONS 06-09-2017 REGISTRATION: FAQ NO. 7)

What is the time limit for taking registration under GST Law

Every Person who is liable to be registered under Section 22 or Section 24 shall apply within 30 days from the date on which he becomes liable to registration in such manner and subject to such conditions as may be prescribed. Further, a casual taxable person or a non-resident taxable person shall apply for registration at least 5 days prior to the commencement of business. Furthermore, every person who makes a supply from the territorial waters of India shall obtain registration in the coastal State or Union territory where the nearest point of the appropriate baseline is located.

(ICAI FAQ PUBLICATIONS 06-09-2017 REGISTRATION: FAQ NO. 3)

Can registration particulars once furnished be amended

Yes, request for amendment has to be made online. All amendments in registration particulars, except some core fields, can be amended in the system without the intervention of any official by merely filing the details of the amendment. Also for some amendments, approval may be needed. Examples of fields which require approval are- legal name of business, address of the place of business and addition, deletion or retirement of partners or directors etc. responsible for day to day affairs of the business. Examples of fields which can be amended without any approval are- change of telephone number, email ID, bank account etc.

(FAQ 21: MSME)