Your CRM says you invoiced a client. Your accounting software says something different. By the time you notice, three weeks of data has diverged, your reconciliation takes a full day, and you're not sure which system is actually true. Most CRM-to-accounting syncs fail silently. They don't error out; they just drift. A field maps wrong here, a rounding rule differs there, and suddenly your pipeline revenue doesn't match your general ledger. You spot it during month-end close, when it's expensive to fix. We've mapped nine sync breaks that hide in almost every CRM-accounting integration. Most are preventable if you know where to look. Here's how to audit whether your sync is reliable—and where to tighten it. 1. Invoice number mismatch: Sequence gaps and format collisions Your CRM auto-generates invoice #1001. Your accounting software generates #1002 because it has its own sequence counter. Now they're forever misaligned. Worse: if your CRM uses a naming pattern like INV-2025-001 and your accounting software expects a plain integer, the sync often truncates or fails silently, and you end up with orphaned records. What to audit: Does your CRM and accounting software share a single invoice sequence, or does each maintain its own? Do you have a naming convention rule in your CRM that your accounting software can parse? Have you tested what happens when the sync reverses—can your accounting software send an invoice back to your CRM without creating a duplicate? Check your last 50 invoices in both systems. Are the numbers contiguous? Are there gaps? Fix: Nominate one system as the authoritative invoice number source. Map your CRM to read the next sequence from your accounting software, not generate its own. 2. General ledger account mismatch: The same revenue, different buckets You create an invoice in your CRM for a software subscription. It posts to GL account 4100 (Software Revenue). But your accounting software's default is 4200 (Service Revenue). The invoice amount is correct, but the GL account is wrong. When you reconcile, the total revenue is right—but it's split between two GL accounts. Your tax accountant pulls a trial balance and finds revenue in both buckets, which breaks your tax calculation and audit trail. What to audit: Does your CRM have a field that maps each invoice to a specific GL account? Is that field required, or can an invoice sync without it? Do you have multiple product lines or service types that should map to different GL accounts? Are they actually mapping correctly? Pull a GL trial balance and group by account. Is all revenue in the account(s) you expect? Fix: Create a lookup table in your sync logic (or in workflow automation ) that maps each CRM product or service type to its GL account. Test with 20 invoices. Make GL account assignment mandatory in your CRM before the invoice can sync. 3. Tax amount discrepancy: Rounding and rate application You invoice $1000 + 10% tax = $1100 total. Your CRM calculates tax at $100. Your accounting software calculates $100.00, but when it rounds at checkout, it records $100.01. That one cent drifts, and after 500 invoices, you have $5 unaccounted for. Worse: if your CRM and accounting software apply tax rates at different stages (one on subtotal, one on subtotal + shipping), the total amount is correct but the tax line is wrong. What to audit: Does your CRM calculate tax, or does your accounting software? What if they both do? Pick 20 invoices with different amounts and tax rates. Calculate tax by hand. Which system matches? Do either system round mid-calculation? At what stage? Does your sync transfer the tax amount or the tax rate ? If it's the rate, rounding may differ between systems. Fix: Designate one system as the tax calculator. Pass the final tax amount (not just the rate) in your sync, so the accounting software uses it without recalculating. Document your rounding rule (round half up, to nearest cent) and enforce it in both systems. 4. Currency rounding: Multi-currency invoices and exchange rates You invoice a Singapore client in SGD. Your CRM records SGD 1430. Your accounting software converts it to USD at 0.74, gets 1058.2, and rounds to 1058.00. But your CRM rounded SGD 1430 at a different point, and now your USD equivalent is 1058.20. Over time, exchange rate rounding creates a drift. What to audit: Do you invoice in multiple currencies? When your CRM syncs to your accounting software, does it send the original currency amount and the exchange rate, or a pre-converted amount? If pre-converted, what rounding rule did your CRM use? What rounding rule does your accounting software use? Pull multi-currency invoices from the past month. Manually recalculate the USD equivalent. Does it match what your accounting software recorded? Fix: Send the original currency amount and the exchange rate (and timestamp) to your accounting software, so it can recalculate if needed. Use a consistent rounding rule across both systems. Better: let your accou