You have two correction paths in MyInvois: (1) cancel within 72 hours of the original validation timestamp — directly in the portal, no credit note needed; (2) after 72 hours, the original is locked — you must issue a credit note (to reduce the amount) or a debit note (to increase it). There is no direct "edit" or "amend" function. The most common mistake: waiting too long, then trying to cancel — and finding the window has closed.
The Three Correction Mechanisms in MyInvois
Malaysian businesses often discover their e-invoice needs correction after it has already been validated by LHDN. A returned shipment. A pricing error. A discount agreed after invoicing. The question is always: what do I do now?
MyInvois gives you exactly three tools — and which one applies depends entirely on timing and the direction of the adjustment.
| Correction Type | When to Use | Time Limit | Direction | Requires New Document |
|---|---|---|---|---|
| Cancellation | Entire invoice is wrong or not needed at all | Within 72 hours of LHDN validation | Voids original completely | No — cancelled in portal |
| Credit Note | Reduce invoice amount — returns, overcharges, refunds, discounts post-invoice | No time limit (after 72h window) | Decreases original value | Yes — Document Type 02 |
| Debit Note | Increase invoice amount — undercharges, additional costs post-invoice | No time limit (after 72h window) | Increases original value | Yes — Document Type 03 |
Read the Malaysia E-Invoice 2025 Complete SME Guide if you're still getting familiar with the base MyInvois workflow. The correction mechanisms only make sense once you understand how validation works.
The 72-Hour Cancellation Window
When LHDN validates your e-invoice, a 72-hour clock starts immediately. During this window, you can cancel the invoice directly in the MyInvois portal — no credit note, no new document, no paper trail beyond the cancellation record.
The 72 hours is calculated from the LHDN validation timestamp, not from when you submitted it or when you noticed the error. If LHDN validated at 2:00 PM on Monday, your window closes at 2:00 PM on Thursday.
When does cancellation make sense?
- You invoiced the wrong buyer — wrong TIN, wrong company name
- You invoiced for goods or services that were never delivered
- Duplicate invoice submitted in error
- Entire transaction cancelled before delivery
One important condition: the buyer must not have already rejected or accepted the e-invoice in their own system. Once the buyer takes action, the 72-hour cancellation path may be unavailable. Always act promptly.
After 72 Hours: Credit Note Is the Only Path
Once the 72-hour window closes, the original e-invoice is locked in LHDN's system. You cannot void it, delete it, or edit it. The only compliant correction is a new document: a credit note (to reduce the amount) or a debit note (to increase it).
This is where many SME owners go wrong. They call LHDN asking how to "fix" an old invoice. The answer is always the same: issue a credit note referencing the original UUID. The original invoice stays in MyInvois — permanently. The credit note creates an offsetting record.
A credit note does not erase the original. It creates an audit trail showing: original invoice issued → correction applied → net amount owed. LHDN, your buyer, and your auditor can all see the full picture.
How to Issue a Credit Note via MyInvois — Step by Step
If you're submitting manually through the MyInvois portal (most common for low-volume businesses), here's the process:
| Step | Action | What to Look For |
|---|---|---|
| 1 | Log in to MyInvois portal (myinvois.hasil.gov.my) | Use your company TIN + digital certificate credentials |
| 2 | Retrieve the original e-invoice | Find via invoice number or date. Copy the IRBM UUID — the unique identifier issued by LHDN at validation |
| 3 | Create a new document — select "Credit Note" (Document Type 02) | Do not use "Invoice" (01) or "Debit Note" (03) — wrong document type voids the correction's legal standing |
| 4 | Populate the credit note fields | Reference document UUID (original invoice), adjustment reason, line items to adjust (quantity or unit price), adjusted amounts |
| 5 | Submit and receive LHDN validation | LHDN will issue a new UUID for the credit note. Keep both UUIDs — original invoice + credit note — in your records |
| 6 | Share the validated credit note with your buyer | Buyer should accept the credit note in their system. The net amount (original minus credit) is the amount legally owed |
Got questions about which e-invoice software automates this process? The E-Invoice Malaysia FAQ covers software selection and common portal questions in detail.
How E-Invoice Software Handles Credit Notes
If you use accredited accounting software, manual portal entry is rarely needed. The major platforms have built this workflow directly into their credit note modules.
SQL Accounting: Create a credit note in SQL's accounts receivable module, link it to the original sales invoice. SQL automatically pulls the IRBM UUID, sets document type to 02, and submits via the MyInvois API. The credit note appears in both your SQL ledger and LHDN's system simultaneously.
Autocount: Similar flow — credit note creation in the AR module, with a mandatory "E-Invoice Reference" field where you enter or select the original invoice. Autocount handles the API submission and logs the new credit note UUID for your records.
Bukku: Cloud-based, so the MyInvois integration is built into the SaaS layer. Bukku's credit note form requires the original invoice selection before you can proceed — it validates that the original was LHDN-approved before allowing a linked credit note.
The takeaway: if you use any of these platforms, your credit note workflow is already MyInvois-compliant by design. The risk of manual errors (wrong UUID, wrong document type) is essentially zero. See the Best E-Invoice Software Malaysia 2025 comparison for a full breakdown of how each platform handles MyInvois integration.
Credit Note vs Debit Note — When to Use Which
The direction of the adjustment determines which document you need. There's no ambiguity.
Use a credit note when:
- Goods are returned by the buyer (partial or full return)
- You overcharged — wrong unit price or wrong quantity on original invoice
- A post-invoice discount or rebate was agreed
- Services were not delivered but already invoiced
- A partial refund is being issued
Use a debit note when:
- You undercharged — wrong price on original invoice, less than the agreed amount
- Additional services were delivered after invoicing and not captured in the original
- Price escalation clauses triggered after invoice date
- Freight or delivery costs added post-invoice
A credit note reduces the buyer's liability. A debit note increases it. When in doubt: ask yourself whether the buyer ends up owing you more or less after the adjustment. More = debit note. Less = credit note.
SST and Service Tax: Adjustments on Credit Notes
If the original invoice included Service Tax (6% or 8%) or Sales Tax (5%/10%), your credit note must adjust both the base amount and the tax portion proportionally.
Example: You invoiced RM10,000 + RM800 Service Tax (8%) = RM10,800. The buyer returns half the goods. Your credit note should show: RM5,000 base credit + RM400 Service Tax credit = RM5,400 total credit.
The adjusted SST is reported in your SST return for the period in which the credit note is issued — not the period of the original invoice. This matters at quarter-end: a credit note issued in July 2025 reduces your Q3 2025 Service Tax output, even if the original invoice was in June.
One edge case to watch: if an SST rate changed between the original invoice date and the credit note date, use the rate that applied to the original transaction — not the current rate. The credit note is reversing the original tax charge, not creating a new one.
Restaurants and service businesses that deal with Service Tax regularly — the E-Invoice for Restaurants Malaysia guide covers how F&B-specific SST obligations interact with MyInvois in more detail.
Common Mistakes When Issuing Credit Notes
These are the errors that cause rejection at LHDN or create compliance gaps:
- Missing the IRBM UUID. The most common error. A credit note without the original invoice's UUID is not a valid MyInvois document — it's just a free-text note. Always copy the UUID from the validated original before creating the credit note.
- Wrong document type code. Using Document Type 01 (Invoice) instead of 02 (Credit Note) means LHDN treats it as a new billable invoice, not a correction. Your buyer gets charged again instead of credited.
- Adjusting the original invoice instead of issuing a new document. You cannot edit a validated e-invoice in MyInvois. Any attempt to resubmit with the same invoice number will be rejected as a duplicate. Issue a credit note as a separate document.
- Forgetting to include SST adjustment. A credit note that reverses the base amount but not the Service Tax creates a mismatch in your SST return — potentially triggering an RMCD query.
- Issuing a credit note but not sending it to the buyer. The buyer needs to accept the credit note in their own system to update their payables. A validated credit note sitting only in your MyInvois account doesn't reduce the amount your buyer believes they owe.
- Using credit notes for currency adjustments. If there's a foreign exchange difference between invoice date and payment date, this is not corrected via credit note — it's a separate accounting entry. Credit notes are for transaction-level corrections only.
Frequently Asked Questions
What is the 72-hour rule for e-invoice cancellation in Malaysia?
LHDN allows you to cancel an e-invoice directly via the MyInvois portal within 72 hours of the original validation timestamp. Cancel within this window and the original document is void — no credit note needed. After 72 hours, you cannot cancel the original. A credit note is the only correction path.
Can I amend an e-invoice directly in MyInvois?
No. There is no direct "edit" or "amend" function. Validated e-invoices are locked. Your options: cancel within 72 hours, or issue a credit note (reduce) or debit note (increase) after the window closes.
What information do I need on a MyInvois credit note?
You must include the original e-invoice's IRBM Unique Identifier Number (UUID), the original invoice date, the adjustment amount at line-item level, the reason for the credit, and Document Type Code 02. Missing the UUID is the single most common rejection reason.
What is the difference between a credit note and a debit note?
Credit note = buyer owes you less (returns, overcharge, refund). Debit note = buyer owes you more (undercharge, additional costs). Both are separate MyInvois documents that reference the original invoice UUID.
How do credit notes affect SST?
If the original included Service Tax or Sales Tax, the credit note must adjust both the base amount and the tax portion proportionally. Report the SST adjustment in the period when the credit note is issued, not the period of the original invoice. Use the SST rate from the original transaction if rates have changed.
Does SQL Accounting, Autocount, or Bukku support MyInvois credit notes?
Yes — all three have credit note modules that sync directly to the MyInvois API. The software handles the UUID reference, document type code, and API submission automatically. Manual portal entry is rarely needed if you use accredited software.
Can I issue a credit note for a B2C consolidated e-invoice?
Yes. Reference the consolidated e-invoice UUID and specify the adjustment for the relevant transaction within the batch. In practice, most B2C returns are processed as point-of-sale refunds rather than formal credit notes. Check with your software provider for the most practical flow for your business type.
Need help with e-invoice corrections or MyInvois compliance?
Credit notes, debit notes, cancellations — getting them wrong creates SST mismatches and audit exposure. We help Malaysian SMEs in Kuala Lumpur, Penang, Johor Bahru and beyond sort out their MyInvois setup correctly. See our e-Invoice compliance service or reach us directly.