compter

From invoice to ledger, on save

Raise the invoice Customer, HSN or SAC code and rate on each line.
The tax decides itself Place of supply picks CGST and SGST, or IGST.
The books post themselves Receivable, revenue and each tax on its own account.
The return files itself GSTR-1 downloads as the JSON the GST portal takes.

INV-2026-0042 B2B Posted

Orbit Agency GSTIN 29ABCDE1234F1Z5 · Place of supply 29-Karnataka

Invoice lines
Item	SAC	Rate	Amount
Brand identity design	998391	18%	₹8,000.00
Website copy	998391	18%	₹2,000.00

Taxable: ₹10,000.00
CGST 9%: ₹900.00
SGST 9%: ₹900.00
Total: ₹11,800.00

Journal entry

1200 Accounts Receivable: Dr 11,800.00
4000 Sales Revenue: Cr 10,000.00
2201 CGST Output: Cr 900.00
2202 SGST Output: Cr 900.00

Most small businesses do their GST twice: once on the invoice, and again in a spreadsheet when the return is due.

compter does it once. The invoice you send is the entry in your books and the line in your return, so the three can never disagree.

One ledger behind every screen

Invoices

Search invoices New invoice

Sample invoice list
Number	Customer	Supply	Total	Status
INV-2026-0042	Orbit Agency	CGST + SGST	₹11,800.00	Paid
INV-2026-0041	Saffron Foods, Pune	IGST	₹2,68,800.00	Sent
INV-2026-0040	Kaveri Textiles	CGST + SGST	₹56,000.00	Overdue
INV-2026-0039	Marina Studio, Chennai	IGST	₹57,600.00	Paid
INV-2026-0038	Walk-in customer	CGST + SGST	₹1,048.95	Paid

GST invoices

Per-line HSN or SAC and rate, place of supply worked out, a PDF with the rupee set properly, and credit notes that reverse exactly.
Statement import

Bring a bank or UPI statement as CSV. Duplicates are flagged and each line lands in an account by what it says.
Reconciliation

Every statement line is matched, partly matched or left for you, and the difference shows until it is zero.
Reports

Balance sheet, income statement and cash flow come straight from the entries, for any date or period.

Type an invoice line

Your business is in Bengaluru, Karnataka. Give an amount, a GST rate and the customer's city, and see what compter posts.

Place of supply 29-Karnataka, same state as you: CGST + SGST

Tax on this line
Taxable value	₹10,000.00
CGST 9%	₹900.00
SGST 9%	₹900.00
Invoice total	₹11,800.00

Posted to the ledger
Account	Debit	Credit
1200 Accounts Receivable	11,800.00
4000 Sales Revenue		10,000.00
2201 CGST Output		900.00
2202 SGST Output		900.00

Debits and credits both ₹11,800.00. Balanced.

Books you can check

The engine is open source

The ledger, the GST maths and the GSTR-1 export live in accounting-core, a Rust crate under the MIT or Apache-2.0 licence. Read exactly how your tax is worked out.

Read the source

let gst = GstCalculator::new(false); // same state
let split = gst.calculate_by_category(
    BigDecimal::from(10000),
    GstCategory::Higher, // 18%
    None,
)?;

assert_eq!(split.cgst_amount, BigDecimal::from(900));
assert_eq!(split.sgst_amount, BigDecimal::from(900));

Every entry balances

Nothing reaches the ledger unless debits equal credits. GST sits on output accounts 2201 to 2203, apart from revenue.

Credit notes, not edits

A sent invoice is never rewritten. A credit note reverses it line by line, and both show in your return.

Set up for India

Your workspace opens with a chart of accounts, GST output accounts and your GSTIN and state on every invoice.

Open the books for your business

Already have one? Sign in