How to Invoice as an IT Consultant
How to bill IT work, step by step: quote fixed-fee projects and collect them in stages, invoice hourly work from tracked time with a timesheet as backup, and keep monthly support on a recurring invoice.
The Bureau of Labor Statistics (US) profiles computer systems analysts on a page it last modified August 27, 2026, and says "Some systems analysts work as consultants." It adds: "Small firms with minimal IT requirements may find it more cost effective to contract with outside firms for these services rather than to hire computer systems analysts directly." If you're an independent IT consultant, one client can give you a project, some hourly work and ongoing support, and each is billed its own way.
This guide takes those one at a time. For more on Billed in this trade, see the IT consulting industry page; the IT consulting invoice template has a layout you can reuse.
Worked example, with sample figures: an email migration for a 12-person office at a fixed fee of 6,000.00, collected on a payment schedule as 3,000.00 at the start and 3,000.00 at go-live in March. In March you also log 4.5 hours of printer and network troubleshooting at 120.00 an hour, or 540.00, and pay 180.00 for a backup software license, recorded as the client's expense so it goes on their next invoice. The 450.00 monthly support fee goes out on its recurring invoice. In March the client is billed 3,000.00 for go-live, 540.00 for hours, 180.00 for the license and 450.00 for support: 4,170.00 in all.
Step-by-step invoicing guide
- 1
Sort the work by how it's billed
Give fixed-fee projects, hourly work and monthly support separate invoices, so the person who approves them can match each one to the work it covers.
- 2
Quote fixed-fee projects on an estimate
Billed's features page says "your clients can approve or reject your estimates online." With the client's approval in hand, you can, as Billed's invoice software page puts it, "convert an approved estimate into an invoice."
- 3
Collect project fees in stages
Billed's help center says "A payment schedule lets you add a payment plan to the invoices." You "Choose a suitable option among percentage or flat amount", and the same article says "the sum of all the payments should be equal to the total balance of the invoice."
- 4
Invoice hourly work from tracked time
Billed's time tracking page says: "Create an hourly rate project, set its hourly rate, and Billed tracks the charge for each task as you log it." It adds: "From the project dashboard you can invoice one task or several at once."
- 5
Back up hourly invoices with a timesheet
Billed's time tracking page says: "Create timesheets from the time you and your team have tracked to see how the team is spending its time, and export them when a client or your accountant needs a copy."
- 6
Keep monthly support on a recurring invoice
Billed's invoice software page says: "For clients you bill on a schedule, set up a recurring profile once. Choose the billing frequency (daily, weekly, monthly or yearly) and how many invoices to send, or keep sending until you stop." Its FAQ adds: "You can choose to send them automatically or save them as drafts to check first."
- 7
Bill licenses and hardware you paid for
Record them as the client's expenses. Billed's help center says "If there are any unbilled expenses of a particular client, you can add these expenses to the client's next invoice." It adds: "The expense will appear as a line item in the invoice."
Tips for it consultant invoicing
- Add the client's purchase order or contract number as a note. Billed's help center describes the notes field as the place for "additional details related to the transaction."
- Describe tasks in plain words (for example, email migration for 12 users), so someone outside IT can approve the invoice.
- Billed's help center says: "Turn on the 'Payment Reminders' option while creating or editing an invoice." It also says "You can set a schedule of payment reminders before and after the invoice's due date."
- Ask an accountant, or look up your state's rules, before you add tax to hardware, software or services.
Common invoicing mistakes to avoid
- Project fees, hourly work and support mixed on one invoice
- Hourly invoices sent with no timesheet behind them
- Extra work outside the project started before a new estimate is approved
- Licenses paid on the client's behalf and never billed
How this works in Billed
Estimates approved online
Quote a project and let the client approve or reject it online.
Payment schedules
Collect a project fee in stages, as percentages or flat amounts.
Hourly rate projects
Log time against tasks and invoice one task or several.
Timesheet export
Export a timesheet when a client wants a copy of your hours.
Recurring invoices
Each month's support invoice can be sent automatically, or kept as a draft until you've looked it over.
Frequently asked questions
Start Invoicing With Billed
Set up your account and send your first invoice with Billed.
At a glance
| Kind of work | Billed as |
|---|---|
| Fixed-fee project | Estimate, then a payment schedule |
| Hourly work | Hourly rate project, with a timesheet |
| Monthly support | Recurring invoice |
| Licenses you paid for | An expense added to the next invoice |
When this isn't for you
If your IT clients pay on time with the invoices you send today, there's no need to switch.