Debit Note (Nota Debit)

A debit note (Nota Debit in Malay) is an adjustment document that increases the monetary value of a previously issued and validated e-invoice. It is the counterpart to a credit note: while a credit note reduces what the buyer owes, a debit note increases it. In the MyInvois framework, debit notes are used when additional charges arise after an invoice has already been validated — for example, if price increases were agreed post-delivery, if additional services were rendered beyond the original scope, or if the original invoice failed to include certain chargeable costs.

Common scenarios for issuing a debit note include: price adjustments where goods were invoiced at a lower price than contractually agreed and the difference must be billed separately; additional costs incurred during delivery or service that were not foreseeable at invoice time (such as extra freight charges or handling fees); shortfall corrections where an invoice was calculated at a lower quantity than actually delivered; and interest charges on overdue payments where the contract specifies such charges.

The key distinction between a debit note and simply issuing a new invoice is one of reference and audit trail. A debit note references the original invoice's UUID, making clear that it is a supplement to an existing transaction rather than a new independent transaction. This linkage is important for both the buyer's and seller's accounting records, for SST reporting (to ensure the additional amount is included in the correct tax period), and for LHDN audit purposes. A new invoice, on the other hand, would represent a separate, standalone transaction.

The MyInvois submission flow for a debit note mirrors that of a credit note. The debit note is prepared as a separate UBL 2.1 document referencing the original invoice UUID, containing the additional amount and applicable tax, and submitted through MyInvois for validation. Once validated, it receives its own UUID. Both supplier and buyer can see the debit note in their MyInvois dashboard linked to the original invoice. The buyer must agree to receive the debit note — in cases of dispute, the buyer may reject the debit note within the 72-hour window.

From a tax perspective, debit notes that increase the taxable supply amount require corresponding adjustments to SST output tax for the supplier and, for the buyer, an increase in claimable input tax. These adjustments must be reported in the relevant SST return period. Businesses with high volumes of post-invoice adjustments should ensure their accounting software handles the debit note workflow automatically to avoid manual errors in tax reporting.