GST for Small Business in India: The Rules I Work With at Our Mill

The Registration Line, and Why Your State Matters

Registration is compulsory once your aggregate annual turnover crosses the limit for your state and your kind of supply:

• Goods only: ₹40 lakh in most states. Notification 10/2019-Central Tax, which set this higher limit, left out intra-state suppliers in Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, Puducherry, Sikkim, Telangana, Tripura and Uttarakhand, so the ordinary ₹20 lakh limit applies there (₹10 lakh in the four states below).
• Services, or goods and services together: ₹20 lakh.
• Manipur, Mizoram, Nagaland and Tripura: ₹10 lakh. Section 22 of the CGST Act now treats only these four as special category states for registration; Uttarakhand and five other states were taken out of that definition from 1 February 2019.

I watch this list because Uttarakhand, where our mill is, sits on it: a goods-only business here has to register at ₹20 lakh, not ₹40 lakh. National summaries tend to skip the state detail, so confirm the current limit for your own state at gst.gov.in before you make a compliance decision.

Some businesses must register whatever their turnover:

• Anyone making inter-state supplies of goods, even a single ₹1 sale. Services are treated differently: Notification 10/2017-Integrated Tax exempts a person making inter-state supplies of services until aggregate turnover crosses ₹20 lakh (₹10 lakh in the special category states it names).
• E-commerce operators, and sellers of goods through marketplaces that collect tax at source. Since 1 October 2023, a small seller of goods who stays below the registration limit and sells within one state only can work with an enrolment number instead (Notification 34/2023-Central Tax), subject to its conditions.
• Casual taxable persons (those making occasional taxable supplies in a state where they are not normally based)
• Businesses required to pay tax under the reverse charge mechanism
• Input service distributors
• Non-resident taxable persons

A consultant working only for clients in her own state, below the limit, does not need to register. Billing clients in other states does not change that for a service provider, because of the 2017 exemption above. Selling goods across a state border does: that needs a GSTIN before the first sale.

Voluntary Registration: When It Makes Sense

You can register voluntarily even below the threshold. This makes sense if:

Your clients are GST-registered businesses. They can claim input tax credit on the GST you charge them. A client paying ₹1,00,000 + 18% GST (₹18,000) gets ₹18,000 back as ITC. Your service effectively costs them ₹1,00,000, not ₹1,18,000. If you're not registered and charge ₹1,00,000 flat, there is no ITC for them, but your price is also lower. The registered option makes you a cleaner vendor for B2B clients.

You have significant input expenses. If you're buying equipment, software, raw materials, or services on which you're paying GST, you can offset that GST paid against your output tax. Without registration, that GST paid is a pure cost.

You're planning to grow beyond the threshold. It's operationally easier to register early and build the habit of compliance before the volume picks up.

The downside: once registered, you must file returns regularly and maintain records. There is no easy "pause". Even in a month with no turnover, you must file a nil return.

Your GSTIN and What It Means

When you register, you get a 15-character GST Identification Number (GSTIN). The format: the first 2 digits are the state code, the next 10 characters are your PAN, the 13th is an entity number for that PAN's registrations in the state, the 14th is "Z" by default, and the last is a check character. Every GSTIN issued in Uttarakhand, for example, starts with 05.

This number goes on every GST invoice you issue. Clients use it to verify your registration status and to match their input credit claims.

The Composition Scheme: Simpler but Limited

If your aggregate turnover in the previous year is up to ₹1.5 crore for goods (₹75 lakh in Uttarakhand and seven north-eastern states), you can opt for the composition scheme; a separate composition scheme caps service providers at ₹50 lakh. Verify current limits before you opt in. The rules:

• Pay tax at a flat rate on your turnover (currently 1% for manufacturers and traders, 5% for restaurants, 6% for service providers; verify current rates)
• File quarterly instead of monthly
• Do not collect GST from customers on your invoices: you pay it from your own pocket
• Cannot claim input tax credit
• Cannot make inter-state supplies

The composition scheme reduces the compliance burden. You file a quarterly statement (CMP-08) and one annual return (GSTR-4). But you cannot pass GST on to customers, which means B2B clients cannot claim ITC from your supplies. For a business that primarily serves end consumers and has relatively low input costs, the composition scheme can simplify life considerably.

Regular scheme vs Composition scheme, side by side:

If your input costs are high relative to sales (you buy a lot of GST-bearing inventory or services) or your clients are GST-registered businesses, the regular scheme's ITC usually wins on the numbers even with the extra filing. If your inputs are low and your buyers are end consumers, composition can be simpler.

When I think about this for a business like ours, I start with the buyer, not the rate: much of what our mill sells goes to wholesalers, distributors and other buyers rather than to households. The composition scheme guide sets out the full test.

GST Invoice Requirements

Every GST-registered supplier must issue a tax invoice with specific details. The required elements:

1. Name, address, and GSTIN of the supplier
2. A consecutive serial number (unique invoice number)
3. Date of issue
4. Name, address, and GSTIN of the recipient (if registered)
5. HSN (Harmonized System of Nomenclature) code for goods or SAC (Service Accounting Code) for services
6. Description of goods/services
7. Quantity and unit of measurement (for goods)
8. Total taxable value
9. Applicable GST rate (CGST + SGST for intra-state, or IGST for inter-state)
10. Amount of tax charged (CGST, SGST/UTGST, or IGST separately)
11. Place of supply
12. Signature

For supplies below ₹200 to unregistered buyers, a consolidated invoice can be issued at the end of the day. For services, invoices must generally be issued within 30 days of service completion (45 days for banks and financial institutions).

GST Filing: What You File and When

Under the regular scheme, you have three main returns:

GSTR-1: Outward Supplies

This is a statement of all sales/supplies you made during the period. You list every invoice issued to GST-registered buyers, plus consolidated data on supplies to unregistered buyers.

Filing frequency: monthly (if turnover above ₹5 crore) or quarterly under the QRMP scheme (if turnover up to ₹5 crore). The monthly GSTR-1 is due by the 11th of the following month.

GSTR-3B: Summary Return with Tax Payment

This is the monthly return where you pay your net GST liability. You declare your total output tax, claim your input tax credit, and pay the difference.

GSTR-3B is due by the 20th of the following month for monthly filers. Under QRMP, you pay tax monthly using PMT-06 but file GSTR-3B quarterly.

GSTR-9: Annual Return

Due by 31 December after the end of the financial year. It consolidates all monthly/quarterly filings for the full year. Businesses below a certain turnover threshold are exempt, so verify the current exemption limit on the GST portal.

Each form, the late fees and a sample month are walked through in GST returns for small businesses.

Input Tax Credit: How It Actually Works

ITC is the mechanism that makes GST a pass-through tax for registered businesses. When you buy goods or services for your business and pay GST, that GST becomes a credit you can use to offset the GST you collect from your customers.

Example: You're a design consultant. You pay ₹50,000 for software subscriptions with 18% GST = ₹9,000 GST paid. You charge a client ₹2,00,000 with 18% GST = ₹36,000 GST collected. Your net GST payable = ₹36,000 - ₹9,000 = ₹27,000.

The conditions for claiming ITC:

1. You possess a valid tax invoice or debit note
2. The supplier has filed their GSTR-1 and the invoice appears in your GSTR-2B
3. You have received the goods/services
4. The tax has been paid to the government by the supplier

GSTR-2B decides what you can claim. This is an auto-generated statement that shows all the ITC available to you based on your suppliers' filings. Before claiming ITC in your GSTR-3B, reconcile your purchase records with GSTR-2B. If a supplier has not filed their return, their invoice will not appear in your GSTR-2B, and you cannot claim that ITC (with some exceptions in law; consult a CA for specifics). The input tax credit guide goes deeper into the 180-day rule, blocked credits and the order of set-off.

Blocked credits: some purchases do not qualify for ITC even if you have a valid invoice and business purpose: motor vehicles (with exceptions), food and beverages, club memberships, construction of immovable property (with exceptions), works contract for immovable property, personal consumption. The full list is in Section 17(5) of the CGST Act.

GST for Service Businesses

If you're providing professional services (consulting, IT services, design, legal, accounting, marketing), you're typically in the 18% GST bracket. Some specific services attract different rates; the GST rate schedule is detailed and service-specific.

For inter-state services, IGST applies. For intra-state, CGST + SGST applies at equal halves (so 18% becomes 9% CGST + 9% SGST).

The place of supply rules determine whether a transaction is intra-state or inter-state, which determines which form of GST applies. For services, the place of supply is generally the location of the recipient for B2B transactions.

E-Way Bill for Goods

If your business involves moving goods worth more than ₹50,000 (verify current threshold), you need to generate an e-way bill on the GST portal before the movement begins. The e-way bill travels with the goods and can be checked at state borders and by tax officials. It applies to both sale and movement for job work, branch transfers, and so on. Service businesses typically don't need to worry about this unless they're physically moving equipment. For any business that moves goods by the truckload, as a mill does, it is routine rather than an edge case.

Reverse Charge Mechanism (RCM): When You Pay GST as the Buyer

Most people understand GST as something the seller charges. Under the Reverse Charge Mechanism (RCM), the buyer (you) pays the GST directly to the government, not to the supplier.

Common situations where RCM applies to small businesses and freelancers:

Foreign service imports: When you pay for services from a foreign vendor (Adobe subscription, AWS, Google Workspace billed from a foreign entity, Figma, Zoom) that aren't registered for GST in India, you're required to pay GST on that service under RCM at the applicable rate. For software/professional services, this is typically 18%.

GTA (Goods Transport Agency) services: If you hire a goods transporter and the transporter is a GTA not registered for GST, you pay 5% GST under RCM. In a business that moves goods by hired lorry, this is the reverse-charge line I would check first.

Legal services from individual advocates: If you pay an individual advocate (not a law firm) for legal services, RCM applies.

Security services from unregistered persons: If applicable to your business.

What to do: For each RCM payment, you pay the GST directly via the GST portal (NEFT, challan) and report it in GSTR-3B. You can then claim ITC for the same amount in the same period (if it's for a business purpose and no other ITC-blocking rule applies), making it effectively neutral for most businesses. The key is not to ignore it. Failing to account for RCM on foreign software subscriptions is a common oversight that creates accumulated GST liabilities.

QRMP Scheme: Who Benefits and Who Doesn't

The Quarterly Return Monthly Payment (QRMP) scheme is available for taxpayers with annual aggregate turnover up to Rs.5 crore. Under QRMP:

• GSTR-1: Filed quarterly (not monthly) by the 13th of the month following the quarter
• GSTR-3B: Filed quarterly, but tax is paid monthly through a self-assessment challan (PMT-06) by the 25th of each month for the first two months of the quarter

Who benefits from QRMP:

• Businesses with low transaction volume: few invoices, simple GST situation
• Businesses where monthly GSTR-1 filing is a meaningful time burden
• Service businesses with primarily B2C (consumer) clients where ITC matching is less critical

Who should stay on monthly filing:

• Businesses with B2B clients who need their ITC reflected promptly in GSTR-2B (QRMP's quarterly GSTR-1 delays ITC availability to your clients)
• Businesses actively managing ITC and wanting precise monthly reconciliation
• Businesses with significant input purchases where tracking ITC monthly matters

If you choose QRMP, inform your B2B clients: their ITC from your invoices will only appear in GSTR-2B quarterly, which may affect their cash flow and advance ITC calculations.

Collected GST Is Not Working Capital

If I could give a new GST registrant one habit, it would be this: the GST on your invoices is the government's money from the day you raise the invoice. It sits in the same bank account as everything else, which is exactly why it gets spent.

In a seasonal business the temptation is stronger, because for much of the year a large share of the money is in unsold stock or with buyers who have not paid yet. Credit sales make the GST side sharper. For a business that sells on credit, as ours does, the tax on a taxable sale falls due with the return for the month of the invoice, whether or not the buyer has paid. The GST bill can arrive before the cash that was meant to pay it.

The order I would follow in any business: file a return you have checked, set the net tax aside, and only then treat the rest of the balance as money you can use. At our mill the GST returns are filed every month, and the GST is set aside as it comes in and paid every month, never allowed to slip into the next month. I treat the mill's cash credit the same way: what an account shows is never the same as what the business is free to spend.

A Month Worked Through

Say a business with ₹40 lakh of turnover charges ₹90,000 of output GST on May sales and has ₹75,600 of input credit that is matched in its GSTR-2B. Net payable is ₹14,400, due before filing GSTR-3B by the 20th. A further ₹8,000 of input credit that has not yet appeared in GSTR-2B is parked, not claimed, until it does.

The mistake to avoid here is claiming input tax credit that is not yet reflected in GSTR-2B, or missing the GSTR-3B deadline, which brings interest and late fees. A GST tracker with a GSTR-2B match column makes the parked credit visible, so it gets claimed the month it appears instead of being forgotten.

Mistakes That Create Notices

Not reconciling GSTR-2B before filing GSTR-3B. Many businesses claim ITC based on their purchase invoices without checking whether the supplier actually filed and matched up. If the ITC doesn't appear in GSTR-2B, claiming it can result in notices and demands.

Treating GST collected as business income. GST collected from clients is a liability: it belongs to the government. If your invoice is ₹1,18,000 (₹1,00,000 + ₹18,000 GST), your income is ₹1,00,000. The ₹18,000 is held in trust until you remit it in your GSTR-3B filing.

Missing the filing deadlines. Late fees and interest accumulate. Even nil returns must be filed on time.

Misclassifying the nature of supply. Applying the wrong HSN/SAC code, or wrong GST rate, creates mismatches that trigger notices during scrutiny.

Not maintaining records for the required period. GST records must be maintained for 72 months (6 years) from the due date of the annual return for the relevant year.

Before You Register: A Short Checklist

If your turnover is under the registration limit for your state and you are not selling goods inter-state or through an online marketplace, you may not need GST registration at all. Don't register prematurely and create filing obligations you don't have.

If you do register, the monthly rhythm is:

• Output GST tracked per invoice
• Input credit claimed only once it shows in GSTR-2B
• Net liability set aside, not spent
• GSTR-1 and GSTR-3B filed by their due dates
• Reconcile monthly against your GSTR-2B and against your own sales and purchase records

Quarterly: on the QRMP scheme, confirm the quarterly return and the monthly tax deposits line up. Annually: prepare GSTR-9 where applicable and reconcile the year's books against what was actually filed.

When to Bring In a CA

The GST portal has detailed FAQ sections, and the gst.gov.in website is the authoritative source for rules, rates, and notifications. GST rules have changed frequently since 2017: rates have been revised, compliance procedures updated, and new schemes introduced. What was correct in 2020 may not be accurate today.

For anything beyond basic filing, especially ITC disputes, reverse charge on imports, multi-state operations or export refunds, a GST-registered CA or tax consultant is worth the cost. A missed ITC claim or an avoidable late fee matters at small business margins. At our mill, the routine records sit with the accountant and the professional work with a separately engaged CA, and I keep those two jobs apart on purpose.

My own view is plain: GST rewards the dull monthly habit far more than any clever structure. Reconcile, set the tax aside, file on time, and it stays routine.