Here is how to handle gst computation in tally, step by step — and, at the end, an honest note about when it is worth doing this differently. Menu wording shifts a little between Tally.ERP 9, TallyPrime and individual releases, but the sequence below holds.
How the tax gets computed, and where it goes wrong
Tax on an invoice should be derived rather than chosen. If anyone is selecting a tax head from a list, that is the error waiting to happen.
- Set your own registration state correctly. Every CGST/SGST against IGST decision is made by comparing the place of supply to this, so a wrong state makes every inter-state invoice wrong.
- Hold the tax rate against the item rather than entering it per invoice. An item carries its own rate; an invoice should not need to be told.
- Record the place of supply on the party, so an inter-state customer produces IGST without anyone deciding.
- Enter HSN or SAC against each item at the number of digits your turnover requires.
- Raise one test invoice to a customer in another state and read the result. The tax should have become IGST on its own.
- Raise a second with two items at different rates, and check the tax was computed per line and totalled per head rather than applied once to the total.
- Check the rounding treatment on the total, and keep it consistent — inconsistent rounding across a year shows up as small unexplained differences at reconciliation.
Rates and HSN digit requirements change. Take them from the notification in force rather than from a rate list copied into the software some years ago.
Keeping both, which is often the right answer
If your accountant works in a desktop ledger and is happy there, you do not have to move them. Plenty of businesses raise invoices in one system and hand a clean summary to a practitioner working in another.
The interface between the two is a file — a GSTR-1 summary, or a CSV of invoices — not a platform commitment. Billixo exports CSV, Excel and JSON, and the export works on the free plan.
Change only the part that is actually costing you evenings.
When this is worth doing differently
None of the above is difficult. It is just a lot of setup that has to stay correct, on a machine that has to stay working, maintained by someone who remembers how it was configured.
That is a reasonable cost for a business with an accountant on staff and a stable office. It is a poor fit for a business where the person billing is also the person selling, and where the office computer is whatever laptop is nearest.
Billixo takes the other approach: the GST details are entered once when you sign up, the tax split is derived from the customer’s state on every invoice with nothing to configure, and there is no installation to maintain. It runs in a browser, and the free plan costs ₹0 with no card.
That is not an argument that one is better. It is an argument that they suit different situations, and it is worth knowing which one you are in.
HSN and SAC codes, and how many digits you need
Every line on a tax invoice needs an HSN code for goods or a SAC for services. How many digits depends on your aggregate turnover in the preceding financial year — smaller businesses report fewer digits than larger ones, and B2B and B2C invoices are treated differently.
Because the requirement is tied to turnover and has been tightened in stages, the practical answer is to store the fullest code you can against each product once, and let the software report at the level required. A six-digit code can always be truncated; a two-digit one cannot be expanded.
Billixo keeps the code on the product record and carries it onto every line automatically, and its AI HSN lookup will suggest one from a plain description when you genuinely do not know.
Invoice numbering: one unbroken series per year
The invoice number has to be consecutive, unique within the financial year, and no more than sixteen characters of letters, numbers, slashes and hyphens. Gaps invite questions. Duplicates cause them.
This is the single most common reason a spreadsheet-based billing setup fails an audit: two people billing on two machines, both starting from the last number they remember. A system that issues the number centrally cannot make that mistake.
The series restarts on 1 April, and Billixo restarts it for you rather than waiting to be told.
The AI, and what it is actually for
The useful application of AI to billing is not a chatbot. It is the twenty minutes a day spent retyping things that already exist on paper.
- Scan a supplier bill. Photograph it; the lines, the GSTIN, the tax and the totals come back as a draft you check rather than a form you fill.
- Find the HSN code. Describe the product in plain words and get a code to confirm, instead of scrolling a list of eleven thousand.
- Ask about your own numbers. "What is outstanding over sixty days?" answered from your data, not a manual.
- Write the reminder. A polite, specific chase for an overdue invoice, ready to send on WhatsApp.
Nothing is sent anywhere until you ask for it, and the platform runs on whichever model it has been configured with — including one hosted on your own server.
Where this fits in a working day
Morning: yesterday’s supplier bills get photographed and become purchase records. Through the day: invoices go out as goods do, shared on WhatsApp before the customer has left. End of the week: the receivables list says who to call. End of the month: the GST summary is a download, not a project.
None of that requires a new habit, which is the point. A billing system that needs discipline to work is one that stops working the first busy week.
Free, and what it costs you instead
Free software usually costs you something that is not money: your data held hostage, an export that does not work, ads inside your invoice, or a "free" tier so narrow it is a demo with a login screen.
The line here is drawn differently. Export works on the free plan — CSV, Excel and JSON — because data you cannot get out is not data you own. The invoice is a real compliant invoice, not a sample. The limits are on volume and on the conveniences, not on whether the thing works.
Start free now. If it does not suit you, take your data with you.
Where your data lives
On the server this platform is installed on. Every record carries a company identifier and every query is scoped to the signed-in account at the framework level, so one business cannot read another’s data by any route, including a crafted one.
Sign-in is rate limited, sessions can be restricted to one device per user, and passwords are stored hashed. Exports are available on every plan, free included: if you ever want to leave, your data leaves with you.
Frequently asked questions
Will I lose my data if I move?
No. Export your party and item lists to CSV or Excel, import them in one pass, and carry unpaid invoices as opening balances. Keep the old system readable for a year — most businesses never migrate historic invoices at all.
Why is GST not calculating on my invoice?
Nine times out of ten a master is incomplete: the stock item has no rate or no HSN, the party ledger has no state, or the tax ledgers are not set to the right tax type. Because the most specific setting wins, a rate set at item level will also silently override one set at company level.
Why did an inter-state sale come out as CGST and SGST?
The place of supply on the voucher, or the state on the party ledger, does not match. Correct it on the party master rather than on the voucher, otherwise the next invoice to that customer repeats the error.
Is my data shared with anyone?
No. It sits in this installation, scoped to your company. AI requests only happen when you explicitly ask for one, and nothing is sent anywhere otherwise.
Is it really free?
Yes. The Free plan is ₹0, needs no card and has no expiry. It has volume limits and leaves out the paid conveniences — watermark-free PDFs, GST return exports, the AI features, extra logins — but the invoices it produces are real GST invoices, and you can export your data from it whenever you like.
Start free, decide later
You do not have to choose a plan to begin. Start on Free, use it for as long as it suits you, and upgrade only when a limit actually gets in your way — never automatically, and never because a countdown ran out.
Open the software demo → — or create the free account from the same page.
Read the full details → on the home page, including pricing and the AI features.
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