Already registered dealer – Every Manufacturer or a Service provider or a dealer registered under Central Excise Act or under Service tax law or State Vat law will get automatic Pan based registration number without fresh application.
New Dealer – Dealers crossing the specified threshold limit – Within 30 days from crossing of such limit.
Other than above – Within thirty days from the date on which he becomes liable for registration.
If you don’t have a GST registration under the GST regime, you will not be able to sell or do business with GST registered businesses as you can not provide input tax credit to your buyer.
Also if you are selling to end consumer and your turnover is below the threshold limit of Rs 20 Lakh (Rs 10 Lakh for North-East and Hilly States), you are fairly safe. However if your turnover exceeds such threshold and you done GST certification courses in India , you may invite the commercial tax officers and may have to face severe penalties. And this will not be very difficult for the tax department as they would be knowing the exact amount of purchases that you are making.

Penalities for Non-Compliance of GST

Late Filing of Returns

1. Late fee for monthly returns ins Rs.20/- per day for nil returns and Rs.50/- per day for returns other than nil returns  subject to a maximum of Rs.10,000/-
2. Late fee for not filing annual returns with due date is Rs.200/- per day subject to a maximum  of 0.25% of the taxpayer’s turnover in the relevant state or union territory.

Threshold limit for turnover for registration in GST is as follows
For Goods:  40 lakhs (Rs.20 / 10 lakh for special category states)
For Services: 20 lakhs (Rs.10 lakh for special category states)

Circumstance for levy of interest

1. A person liable to pay tax fails to pay the tax – Interest on the tax due will be calculated from the first day on which the tax was due to be paid
2. A person makes an undue or excess claim of input tax credit or undue or excess reduction in output tax liability – Interest on the undue excess claim or undue or excess reduction
3. A recipient fails to pay to the supplier of goods or service the amount towards the value of the goods or service, along with tax payable thereon, within 180 days from the date of issue of invoice by the supplier – Interest on the amount due will be added to the recipient’s liability.

Circumstance for levy of penalty

Those who have committed the below offences intentionally shall be liable to pay 100% of tax evaded subject to a minimum of Rs.10,000/-. Where there is no fraudulent intent, the penalty shall be 10% of tax evaded subject to a minimum of Rs.10,000/-
1	Supply of goods or services or both without issue of any invoice or issue of an incorrect or false invoice
2	Issue of any invoice or bill of supply in-violation of the provisions of this GST Act or Rules
3	Collects any amount as tax but fails to pay the same to the Government within a period of 3 months from the date on which the payment becomes due
4	Collects any tax in contravention of the provisions of GST Act but fails to pay the same to the Government within a period of 3 months from the date on which the payment becomes due
5	Fails to deduct tax or deducts an amount which is less than the amount required to be deducted or fails to pay to the Government, the amount deducted as tax
6	Fails to collect tax or collects an amount which is less than the amount required to be collected or fails to pay to the Government, the amount collected as tax
7	Avails or utilizes input tax credit without receipt of goods or services or both
8	Fraudulently obtains refund of GST
9	Takes or distributes input tax credit in contravention of the provisions of GST Act or rules
10	Falsifies or substitutes financial records or produces fake accounts or documents or furnishes any false information or return with an intention to evade payment of tax
11	Is liable to be registered under GST Act but fails to obtain registration
12	Furnishes false information at the time of applying for registration
13	Obstructs or prevents any officer from performing his duties under GST Act
14	Transports any taxable goods without required documents
15	Suppresses his turnover leading to evasion of GST
16	Fails to keep, maintain or retain books of accounts and other documents in accordance with the provision of GST Act and rules
17	Fails to furnish information or documents or furnishes false information or documents during any proceedings under GST Act
18	Supplies, transports or stores any goods which he has reason to believe are liable to confiscation under GST Act
19	Issues any invoice or document by using GSTIN of another person
20	Tampers with or destroys any material evidence or document
21	Tampers with or deposes off any goods that have been detained, seized or attached under GST Act

Circumstances for Cancellation of Registration certificate

• A regular dealer has not furnished returns for a continuous period of 6 months.
• A composition dealer has not furnished returns for 3 quarters.
• A person who has taken voluntary registration has not commenced business within 6 months from the date of registration.
• Registration has been obtained by fraud, willful misstatement or suppression of facts.