First 30 Days After GST Registration: Invoice, GST Portal, Bank, Filing and ITC Checklist

A new GSTIN is only the start. Use this first-30-days checklist to download REG-06, set invoices, update bank and marketplace records, configure HSN, track first returns, and avoid nil-return penalties.

5 June 2026 9 min read

Key Takeaways

After GST approval, download Form REG-06, verify legal details, display the certificate, and update invoice, bank, website, and marketplace records.
New taxpayers should track GSTR-1, GSTR-3B, ITC, HSN, invoice series, and nil-return requirements from the first tax period.
Bizeract links GST registration with first-month filing so the business does not get a GSTIN and then miss its first compliance cycle.

By Mani MuruganFinance & GST Lead · 10+ yrs experience

The first 30 days after GST registration decide whether your new GSTIN becomes an asset or a compliance problem. Approval is only step one. You still need Form REG-06, invoice setup, portal access hygiene, first return planning, ITC review, and updates across banks, marketplaces, websites, and customers.

The GST portal's GSTR-8 FAQ says e-commerce operators report TCS for supplies made through their platforms by registered taxable persons (GST Portal, 2026). That is one example of why post-registration setup matters immediately for sellers.

Day 1: download and verify your GST certificate

Download Form REG-06 after approval and check legal name, trade name, constitution, principal place of business, additional places, effective date, and authorised signatory. A wrong field should be fixed through amendment quickly, because invoices, bank records, and marketplace accounts will copy these details.

Save the certificate PDF in your accounting folder, share it with your CA, and display it at the principal place of business. If you registered for a marketplace or B2B client, upload the certificate before onboarding expires.

Week 1: set invoice format, HSN and tax rates

GST registration allows you to collect tax, but your invoice must show the right GSTIN, invoice number, date, buyer details, HSN or SAC, taxable value, CGST, SGST, IGST, and total. Small invoice mistakes become GSTR-1 mismatches later.

Create one invoice series for the financial year.
Map every product or service to HSN/SAC and rate.
Decide tax-inclusive or tax-exclusive pricing.
Set credit-note process for returns and cancellations.
Use the GST invoice generator for clean first invoices.

Week 2: update business records everywhere

Your GSTIN should appear consistently wherever business identity is used: invoices, website footer, payment gateway, bank profile, marketplace seller account, purchase orders, quotation format, email signature, and accounting software. Consistency reduces buyer and ITC friction.

For marketplace sellers, update Amazon, Flipkart, Meesho, ONDC, Shopify, WooCommerce, or quick-commerce seller records before the first taxable order. For service providers, tell B2B clients your GSTIN and invoice format before the next billing cycle.

Week 3: plan GSTR-1 and GSTR-3B before the due date

New GSTIN holders must file applicable returns from the first tax period, even when there are no sales. GSTR-1 reports outward supplies, while GSTR-3B summarises tax liability, ITC, and payment. Missing a nil return still creates late-fee risk.

Keep a monthly file with sales register, purchase register, expense invoices, payment gateway statements, e-commerce reports, and bank entries. If the business has no transactions, record that decision and file nil returns where required.

Do these in order. Most first-month GST errors come from skipping invoice setup or nil-return planning.

Week 4: review ITC and first-month purchases

Input Tax Credit is valuable, but do not claim blindly. Review purchase invoices, supplier GSTIN, GSTR-2B reflection, business use, blocked-credit rules, and whether any stock or pre-registration purchase qualifies under the specific ITC provisions.

The practical habit is to create a purchase folder from day one. Save software invoices, rent, professional fees, inventory, packaging, courier, ads, and equipment bills with GSTIN. Then let the CA decide eligible ITC during filing.

What Bizeract bundles with first-month filing

Registration and filing are separate. That is why the Bizeract GST registration with filing offer pairs the GSTIN process with first-month compliance. The goal is to prevent a business from getting approved and then missing the first return cycle.

GST certificate download and detail check.
Invoice format, HSN/SAC, and tax-rate setup.
First GSTR-1 and GSTR-3B planning.
ITC document review and bookkeeping folder setup.
Next-step links: monthly GST filing, bookkeeping services, and registration vs filing guide.

What to verify before acting on First 30 Days After GST Registration

Rules and platform behaviour change after an article is published. Confirm thresholds, registration status, return forms, document rules, and portal notices against the GST Portal before you act on anything below, because the right answer depends on your entity, state, turnover, and current setup.

Going deeper: GST Registration, GST Return Filing, and Bookkeeping Services.

Frequently asked questions

What should I do immediately after GST registration is approved?

Download Form REG-06 from the GST portal, verify legal name, trade name, address, constitution, and effective date, save the certificate, display it at the place of business, and update invoice templates, bank records, website footer, marketplace accounts, and accounting software.

Do I need to file GST returns in the first month?

Yes. Once registered, return obligations begin for the applicable tax period, even if there are no sales. File nil returns where required, or file actual GSTR-1 and GSTR-3B with sales, ITC, and tax payment details.

Can I claim ITC on purchases made before GST registration?

ITC rules depend on timing, stock, invoice dates, and Section 18 conditions. Do not assume every pre-registration purchase is eligible. Prepare opening stock, invoice copies, and accounting records for a CA review before claiming transitional or first-month ITC.

Why bundle GST registration with first-month filing?

Registration creates recurring compliance immediately. A first-month filing bundle helps new businesses set invoice series, HSN codes, books, ITC review, GSTR-1, and GSTR-3B correctly before small mistakes turn into notices or late fees.