You close a deal, issue an invoice, and expect the accounting department to post it cleanly to the general ledger. What actually happens is far messier. The invoice sits at ₹100,000. The GL entry lands as ₹98,500 revenue, ₹1,200 COGS, ₹200 tax payable, and ₹100 discount. Now you're hunting—and the reconciliation takes six hours because no one documented where the splits came from. By month-end, you have seventeen orphaned line items and a CFO who's stopped trusting the numbers. This isn't a bug. It's the collision between billing logic and accounting logic. Billing sees one invoice. Accounting sees multiple GL lines. Neither system knows why the other exists. The fix isn't a better spreadsheet. It's mapping the nine splits that consistently break reconciliation, building a documented audit trail, and automating what you can. The nine GL splits that create reconciliation breaks Each of these is a place where your invoice total and your GL balance diverge. Most companies catch three or four. The others hide until tax season or an audit. 1. Tax rounding (₹0–5 per invoice) You invoice ₹10,000 plus 18% GST = ₹11,800. But line-item tax is calculated separately: if you have three line items, each gets rounded independently. One line might be ₹3,536.18, another ₹3,536.19, the third ₹3,536.18. Total tax ₹636.55—not ₹636 exactly. The invoice shows ₹11,800.55. Your GL entry says ₹11,800. The ₹0.55 doesn't reconcile. Multiply by 2,000 invoices a month and you have ₹1,100 floating. 2. Multi-currency conversion (₹50–2,000 per invoice) You invoice SGD 800 to a Singapore client. Your billing system converts it to INR at the rate on invoice date (1 SGD = ₹63.5 = ₹50,800). Your GL uses the rate on payment receipt date (1 SGD = ₹63.8 = ₹51,040). The invoice reconciles at ₹50,800. The GL posts at ₹51,040. You have a ₹240 gain or loss that didn't come from the client—it came from timing and which rate the system chose. 3. Retainer allocation across months (₹500–15,000) A client pays ₹50,000 retainer upfront in January. You issue monthly invoices drawing against it. Your billing system shows ₹50,000 invoice in January, ₹0 invoice in February. Your GL needs ₹50,000 deferred revenue in January, ₹12,500 revenue each month February–May. The invoice total (₹50,000) never matches the monthly GL revenue (₹12,500). This isn't wrong—it's by design. But if you don't document it, you'll spend two weeks finding it. 4. Project overages and auto-invoicing (₹0–8,000) A client's project was budgeted at ₹100,000. Actual time was ₹112,000. Your billing system auto-generated an invoice for ₹12,000 overage on the 15th. Your CRM deal still shows ₹100,000 committed. The GL has ₹112,000 revenue. The invoice is ₹12,000. None of these numbers match the others. Three systems, three truths. 5. Discount applied after invoice (₹200–5,000) You issued an invoice for ₹100,000. Client paid late. You issued a credit note for ₹2,000 goodwill discount. Your billing system now shows total invoiced = ₹100,000, total paid = ₹98,000. Your GL shows revenue ₹98,000 (the discount was posted as a revenue reversal). The invoice table and the GL don't match because one is a cumulative record and the other is a transaction record. 6. Partially captured payment vs invoice You invoice ₹50,000. Client pays ₹30,000 on the due date, ₹20,000 two weeks later. Your billing system may show one invoice with a partial payment status. Your GL shows revenue ₹50,000 on invoice date and cash ₹30,000 on payment date 1, ₹20,000 on payment date 2. The invoice line-item GL splits (revenue, tax, COGS) all post on invoice date, but the cash-basis GL entries post on payment dates. They don't synchronize. 7. COGS allocation for bundled services (₹500–8,000) You invoice a package: ₹10,000 professional services + ₹20,000 software license. Your billing system posts the invoice as one line. Your GL needs ₹10,000 revenue and ₹6,000 COGS (60% cost) for services, and ₹20,000 revenue and ₹0 COGS for the license. The invoice is ₹30,000. The GL revenue is ₹30,000 (matches), but COGS is ₹6,000 (where did it come from?). If no one documented the allocation rule, the next invoice follows a different rule and the GL never reconciles. 8. Tax on discounts or late-payment interest (₹10–500) You invoice ₹100,000 + ₹18,000 tax. You offer a ₹5,000 early-payment discount. The question: is tax recalculated? Is it 18% of ₹95,000 = ₹17,100, or do you credit ₹900 tax as well? Different systems (and different invoicing rules by state) answer differently. Your invoice might show ₹95,000 + ₹17,100 = ₹112,100. Your GL might post ₹95,000 revenue, ₹900 tax reversal, ₹17,100 tax payable. The invoice total ₹112,100 and the GL revenue ₹95,000 diverge. 9. Item-level tax rates (₹50–2,000) You sell a mix: ₹50,000 product (18% GST), ₹30,000 service (12% GST), ₹20,000 exempted item (0% GST). Invoice total = ₹50,000 + ₹9,000 + ₹30,000 + ₹3,600 + ₹20,000 = ₹112,600. Your GL needs four line items: product revenue, product tax, service rev