Software maintenance invoice
Invoice template for developers on a support contract: monthly bug fixes, security patch deployment and incident response. Download it as Excel or Word.
Templates by industry
- Monthly bug fixes
- Security patch deployment
- Incident response
Preparation guide
Example workflow
Confirm scope and quantities
Example: reconcile the approval and work record for "Monthly bug fixes" to establish the quantity for this invoice.
Record delivery and acceptance
Check completion for every line, including "Incident response". Deliver the agreed test results and configuration notes, and assign owners for outstanding items.
Send the billing record
Send the final charges, delivery reference and due date to the customer, then reconcile payment against the invoice number.
A maintenance invoice usually follows a support contract: a fixed monthly fee for keeping software running, plus time for incidents beyond what the fee covers. The template separates routine bug fixing, security patches and incident response, because clients read them differently: the first two are expected every month, the third shows how often something went wrong. It fits agencies and freelance developers who look after a client’s website, app or internal system after launch.
Fields to prepare
- Deliverables and line items
- Monthly bug fixes, Security patch deployment, Incident response: record the quantities actually supplied and the service period.
- Monthly bug fixes
- Bill the month as one line at the contract fee and list the ticket numbers closed, rather than pricing each fix.
- Security patch deployment
- Name the components patched and the date they went live, for example “framework security release, applied 9 May”.
- Incident response
- Give the incident date, the time to restore service and the hours spent, and say if it fell outside business hours at a higher rate.
- Environment and dependencies
- Record target systems, integration counts, data volume and who supplies test access.
- Acceptance and support
- Set acceptance scenarios, the review window, support duration after handover and excluded work.
- Scope to agree
- Record the billing month, resolved defects and patches, and incident-response time; identify new feature work separately.
Before sending
- Does “Monthly bug fixes” show the quantity actually supplied, not the quantity first quoted?
- Is “Security patch deployment” charged at the rate the customer agreed to, with any change approved?
- Is “Incident response” finished and accepted, or does it belong on a later invoice?
Show 3 more
- Separate third-party service charges from implementation fees.
- Agree who handles the production transition and what recovery work is included if it fails.
- Match completed work to the order or approval record, and confirm the payment due date and amounts already received.
Worked example with sample figures
The figures below are invented to show how the template adds up: 3 lines in USD, with an example tax rate of 8%.
| Item | Quantity × unit price | Amount |
|---|---|---|
| Monthly bug fixes | 6 × $450.00 | $2,700.00 |
| Security patch deployment | 1 × $750.00 | $750.00 |
| Incident response | 20 × $300.00 | $6,000.00 |
| Subtotal | $9,450.00 | |
| Sales tax (8%) | $756.00 | |
| Total | $10,206.00 | |
Net amount $9,450.00, sales tax $756.00, total payable $10,206.00.
What the document must show
The details an invoice has to show, and why each one matters, are set out in the guide below.
The sales tax depends on where the work is supplied, so set the rate that applies to your customer before sending.
Official rate reference: US government: state and local taxes
Full requirements: How to write an invoice: a step-by-step example
Frequently asked questions
The client asked for a new feature during the month. Does it go here?
Not under maintenance. Quote the feature separately and bill it on its own line or invoice once it is approved, so the monthly fee keeps meaning the same thing from one month to the next.
What if no incidents happened this month?
Leave the incident line off rather than showing it at zero. An invoice with only the fixed fee and the patches is normal, and it tells the client the month was quiet.
How do I show support hours included in the contract?
If the contract includes a block of hours, state in the notes how many were used and how many roll over or lapse under the contract terms, so both sides track the balance the same way.
How is the sales tax worked out on this invoice?
The worked example above uses an example rate of 8%: $756.00 on a net amount of $9,450.00, for a total of $10,206.00. The editor recalculates all three when you change a quantity, a price or the country.
Can I add my logo and signature?
Yes. The From section of the editor has a place for your company logo and for a signature or seal image. Uploading a picture needs a free account, and a member can keep both in settings so that every new document starts with them.
Read next
Reading for the Software maintenance invoice: How to write an invoice: a step-by-step example and Credit note vs invoice (and credit memo): how to issue one. The VAT and GST calculator works out the tax line for you.