Different considerations.
FOR GOODS
Description, quantity, unit price, total Delivery details Any warranty terms
FOR SERVICES
What was done, over what period Hours or a fixed fee What is included and excluded
THE DESCRIPTION MATTERS MORE FOR SERVICES
A vague service description invites questions and delays payment.
"As agreed" is not a description.
FOR HOURLY WORK
Show the hours and the rate.
Customers query totals they cannot reconstruct.
FOR FIXED-FEE WORK
Reference the agreement or quotation.
FOR RECURRING SERVICES
State the period covered explicitly. "Maintenance, March 2026".
FOR EXPENSES RECHARGED
Itemise them, with receipts attached if the customer requires.
Agree in advance which expenses are rechargeable.
WHAT TO AVOID
Invoicing for work outside what was agreed, without discussing it first.
That is the most common cause of disputed service invoices.
