What is Debit Note?
A document issued to notify a buyer of additional charges or adjustments to an originally issued invoice.
Definition
A debit note is a commercial document issued by a seller (or service provider) to a buyer that notifies them of additional charges, corrections, or adjustments to a previously issued invoice. Unlike a regular invoice — which creates the initial payment obligation — a debit note formally increases the amount owed or records a debit entry in the buyer's account. Debit notes are commonly used when an original invoice understated the correct amount, when additional goods or services beyond the original scope have been delivered, or when a pricing adjustment is needed after the fact.
When and Why Debit Notes Are Used
Debit notes are most common in B2B transactions, manufacturing, and supply chain contexts, but freelancers may encounter them in several situations. If the freelancer underpriced a line item due to an error, a debit note corrects the shortfall. If a client requests additional work outside the agreed scope and the freelancer needs to bill for those extra hours after the original invoice was sent, a debit note formally captures those charges. In some countries, debit notes are legally required for certain types of tax adjustments. They provide a clear paper trail for accounting purposes and protect both parties by documenting why additional charges were applied.
Debit Note Example
A freelance digital marketing consultant sends a monthly retainer invoice for $3,000 covering 20 hours of ongoing work. At the end of the month, the consultant also ran a paid advertising campaign for the client, which incurred $450 in ad spend that was paid out of the consultant's account on the client's behalf. Rather than sending a separate full invoice, the consultant sends a debit note for $450 referencing the original invoice, with a note explaining: "Reimbursement for ad spend incurred on your behalf, per our agreement." The client pays the debit note alongside the original invoice.
Debit Note vs. Credit Note
A debit note increases the amount owed by the buyer — it is essentially an additional charge. A credit note (or credit memo) decreases the amount owed — it is issued to cancel, reduce, or refund an existing invoice. If a freelancer undercharged a client, they issue a debit note to collect the shortfall. If a freelancer overcharged or needs to cancel an invoice, they issue a credit note. Both documents must reference the original invoice they are adjusting for proper accounting records.
Best Practices for Debit Notes
Always reference the original invoice number on a debit note so the buyer can easily reconcile the charge. Clearly explain the reason for the additional charge on the debit note. Send the debit note promptly after discovering the discrepancy — waiting months to issue a debit note increases the likelihood of a dispute. For freelancers, keep debit notes in your accounting records as supporting documentation for the additional revenue. Eonebill makes it easy to generate a debit note that references the original invoice and clearly itemizes the additional charges.