Three dates run a Mumbai GSTIN. The 11th of each month closes GSTR-1, the 20th closes GSTR-3B for monthly filers, and quarterly filers under QRMP in Maharashtra answer to the 22nd after the quarter ends. Miss any of them and the meter starts the next morning: daily late fees, interest on the unpaid tax, and buyers whose credit now depends on your delay. GST return filing in Mumbai is the discipline of never letting that meter start. LegalX India runs the cycle from ₹299 a month, with a CA reviewing every return before it leaves for the portal.
What will GST return filing cost you in Mumbai?
Start with what is free. The government charges nothing to file a return on gst.gov.in, and any portal fee you have been quoted was invented by the person quoting it. What you actually pay for is the work behind the numbers: pulling sales and purchase data together, matching credit against what suppliers reported, and catching errors before submission rather than after a notice.
Our fee starts at ₹299 per month for a standard cycle covering GSTR-1 and GSTR-3B, and your CA confirms the exact figure once your transaction volume is clear. Weigh that against the other column. A mismatched credit claim invites a reversal with interest. A missed period stacks late fees daily until someone finally files. For the forms, schemes and fee schedules that apply across the country, read the full GST return filing process nationwide. This page stays on what changes when you file from Mumbai.
Do the thresholds catch your business?
Registration in Maharashtra follows the normal category limits: ₹40 lakh annual turnover for goods and ₹20 lakh for services. Cross either line and registration stops being optional. Many businesses register below the line anyway, because serious buyers prefer vendors whose invoices carry usable credit.
The threshold question ends the day your GSTIN is issued. From that point the filing duty attaches to the registration, not to the turnover, and a month with zero sales still owes a return. A fund consultant in BKC who crossed ₹20 lakh in advisory fees two years ago carries the same monthly duty as a jewellery wholesaler in Zaveri Bazaar turning many times that figure. The difference lies only in how much reconciliation each cycle demands.
How does the Maharashtra layer behind your GSTIN work?
Every Maharashtra GSTIN begins with 27, and behind that state code sits an officer assignment most owners never notice until a query lands. At registration your file went either to the Maharashtra Goods and Services Tax Department, the state administration working through mahagst.gov.in, or to a Central GST officer in the Mumbai zone. Returns are filed on gst.gov.in either way, but clarifications, scrutiny and physical verification of your premises come from whichever side holds the file. We identify your assignment before drafting a reply to anything.
The state then adds a second track that national guides skip: profession tax. Every company and LLP in Mumbai takes PTEC on incorporation, a flat ₹2,500 a year owed by the entity itself, with no return attached. Each director carries a personal PTEC too. PTRC is the separate employer certificate for deducting from staff salaries, ₹200 a month per liable employee and ₹300 in February, with women earning up to ₹25,000 a month exempt from the deduction. Both certificates sit on mahagst.gov.in, and we calendar them beside your GST dates so neither slips while you watch the other.
Which documents and proofs matter most in Mumbai?
The proof that decides most Mumbai files is the principal place of business. A large share of the city's businesses operate from premises held under leave and licence or inside a cooperative housing society, and officers read those papers closely when they verify an address. The papers have to tell one story:
- The leave and licence agreement itself, current and clearly covering business use of the premises
- The licensor's NOC permitting your firm to operate and register from the address
- The society's position, because an objecting housing society can unsettle an otherwise clean file
- Ownership proof or a utility bill when the premises are your own, which is the simpler case
Section 55 of the Maharashtra Rent Control Act, 1999 makes leave and licence agreements compulsorily registrable, with the obligation on the landlord, so an unregistered agreement makes a weak anchor for a GSTIN. The monthly side is shorter: sales register, purchase register and portal credentials. Send those three and your CA handles everything that follows.
Which deadlines govern your returns?
Print this and pin it near whoever raises your invoices. The table assumes a standard Maharashtra GSTIN, and we confirm your scheme status each quarter before applying it.
| Filing | Who it binds | Due date |
|---|---|---|
| GSTR-1 | Monthly filers | 11th of the following month |
| GSTR-3B | Monthly filers | 20th of the following month |
| GSTR-3B under QRMP | Quarterly filers in Maharashtra | 22nd after the quarter ends |
| PTRC returns | Employers registered for salary deduction | Frequency set by prior year liability |
| PTEC payment | The entity and each director | The annual due date, no return attached |
Interest on unpaid tax runs from the due date no matter when the return finally goes in. That is why we file even an imperfect month on time and correct it through the following cycle where the law permits, rather than holding a return hostage to one missing invoice.
What trips Mumbai filers up?
The problems we untangle for new Mumbai clients repeat with remarkable consistency:
- Working to the wrong QRMP date because a national checklist said one thing and the Maharashtra grouping says the 22nd.
- Claiming credit straight from the purchase register without matching the auto drafted statement, then absorbing a reversal with interest.
- Treating profession tax as covered because GST is filed, when the certificates on mahagst.gov.in run on their own calendar entirely.
- Letting premises paperwork drift, a renewed leave and licence never updated on the portal, until a verification visit finds the mismatch.
- Assuming exports need no attention. A SaaS founder in Powai billing US clients still files every period, and zero rated invoices must appear in GSTR-1 before any refund moves.
Each of these is cheap to prevent and expensive to repair. The monthly retainer exists so that prevention is somebody's actual job.
Why LegalX India for Mumbai GST work?
Because the filing is national but the failure points are local, and we sit on both sides of that line. Our CA and CS team files for 15,000+ clients across India. The work rates 4.8 on Google across more than 2,500 reviews, and GST returns are the steadiest part of it. The Mumbai presence is real: an office on the second floor of Haware Fantasia Business Park in Vashi, Navi Mumbai. Visit if you prefer sitting across a table from an expert, though every return can be handled without leaving your desk. Jurisdiction always follows your registered address, never ours.
Pricing stays transparent from the first conversation. Share your GSTIN and the last period's data, and you get a callback within 30 minutes, a clear fee, and one calendar covering GST and the Maharashtra certificates together. The 20th stops being a date you dread.