MyInvois doesn't bounce invoices back with an error message. It silently swallows them. Your tax authority sees nothing. Your accounting team sees nothing. Your customer sees an invoice that looks perfect. But the government record stays blank—and when April rolls around, you're stuck reconciling a month of invoices that never actually registered. The silence isn't random. MyInvois fails on three specific, auditable failure modes: malformed tax IDs, miscalculated tax rates, and missing or corrupt metadata fields. Each one can be found and fixed in a single afternoon. Each one you miss becomes a compliance risk and a reconciliation headache. Run this audit now—before March tax season begins—and you'll spend April closing books instead of forensic invoice hunting. Why MyInvois silently rejects Malaysia's MyInvois system (the e-invoicing standard for GST-registered businesses) validates invoices against LHDN specifications when they're submitted. If validation fails, the invoice sits in a rejected state—but your system may not surface that rejection clearly. No bounce email. No pop-up warning. Just: invoice created, invoice submitted, invoice... not registered. The issue compounds because most invoicing platforms don't flag MyInvois rejections in real time. By the time you export logs and check for failures, you've issued 200 invoices, and 8–15 of them are invisible to the tax authority. The risk: An invoice that looks correct to your eye—correct number, correct total—will fail MyInvois validation silently, and you won't know until reconciliation time. The three failure modes (and how to spot them) 1. Tax ID format errors MyInvois demands tax IDs in a specific format. A misplaced digit, an extra space, or a typo—even a common one—causes silent rejection. BRN (Business Registration Number): Must be 12 digits, no spaces, no letters. 123456789012 , not 12-3456-789012 or 123 456 789 012 . ID number (for sole traders or individuals): Must be a valid Malaysia MyKad or passport format, with correct check digits. NRIC (National Registration Identifier): Must include the hyphen in the correct position: 123456-12-1234 , not 12345612-1234 or 1234561212340 . How to audit: Export your last 100 invoices (or your full backlog if under 500). Pull the tax ID field for each. Check for inconsistent formatting, leading/trailing spaces, or typos. Run a regex test against LHDN specs. A single invoice with a 10-digit BRN instead of 12 will fail. 2. Incorrect tax calculation MyInvois doesn't just check that a GST amount exists—it validates that the GST calculation is mathematically correct based on the invoice line items, tax rate, and exemption flags. GST rate mismatch: A line item marked as 6% GST, but the invoice total assumes 0%. MyInvois catches this. Rounding errors: GST calculated to three decimal places when MyInvois expects two. Or vice versa. Exemption inconsistency: A line item flagged as GST-exempt, but GST added anyway. Or GST withheld and GST charged on the same invoice without explicit exemption coding. Multi-rate invoices: If you invoice on a single invoice at two tax rates (e.g., a retainer at 6% GST + a project component at 0% export), the totals must reconcile line-by-line. Miscalculation here is common. How to audit: For each of your last 100 invoices, manually recalculate the GST. Pick a line item. Multiply the net amount by the GST rate. Check that it matches the invoice total. If it doesn't—if you see a difference of even RM0.01—MyInvois will reject. Pay special attention to invoices with multiple tax rates or exemptions. 3. Missing or malformed metadata fields MyInvois requires specific fields to be present and formatted correctly, even if they seem optional in your invoicing software. Invoice type code: Must be one of: 01 (Tax Invoice), 02 (Debit Note), 03 (Credit Note), etc. An empty field or non-standard code fails silently. Document type: For Credit Notes or Debit Notes, the reference invoice number must exist and be valid. A reference to an invoice number that was never submitted (or was rejected) causes the note to fail. Customer tax ID: If the customer is GST-registered, their ID must be provided and valid. If missing when required, MyInvois rejects. If provided in an invalid format, MyInvois rejects. Payment terms and due date: Some invoice templates omit payment terms. MyInvois requires this field; missing it causes rejection. Currency code: Must be MYR or a valid ISO 4217 code. Typos here are rare but catastrophic. Item descriptions and line-level tax codes: Each line item must have a description, a quantity, a unit price, and a tax code (e.g., 01 for taxable, 02 for exempt). Missing any of these fails the invoice. How to audit: Export a sample of 20 invoices (5 invoices from each month if you have a backlog). Open them in your invoicing platform or as JSON/XML if your system supports export. Verify: invoice type code is populated, customer tax ID is present (if they're GST-registered), payment terms