Keep each consulting engagement easy to bill
Reuse the billing contact and engagement reference, then review days worked, milestones or the retainer period. Track what remains unpaid after recording confirmed payments.
Built for independent consultants and advisory firms · Mobile and web · No InvoiceSonic transaction fee
One record from agreed work to payment — Bill fixed deliverables, day rates or a recurring monthly retainer with separately approved expenses. Keep the statement-of-work, purchase-order or engagement number and the billing period on the invoice so the client can approve it without asking what the charge covers.
Enter the actual job details, review the totals and preview your invoice. You can start without an account. Downloads follow the free-tool limits; saving, tracked sending and reminders are available with an account.
Reuse the descriptions independent consultants and advisory firms actually bill: discovery workshop, advisory days, report or deliverable milestone, monthly retainer and reimbursable expenses. Totals and tax recalculate automatically.
Carry the agreed scope into the invoice and show deposits or staged payments separately, rather than rebuilding the price from memory.
Put the statement-of-work, purchase-order or engagement number and the billing period on the invoice so the customer, broker or bookkeeper can match it quickly.
Track sent, viewed, partially paid, paid and overdue invoices from one list instead of cross-checking email and a spreadsheet.
State deposit or advance retainer for new clients, then Net 14 or Net 30 for approved work; if the balance passes that date, a polite reminder can go out automatically.
Add bank transfer, PayID, Venmo, Zelle, Cash App or PayPal details. InvoiceSonic never takes a percentage of the invoice.
Choose the customer and carry across the agreed price, scope and statement-of-work, purchase-order or engagement number and the billing period.
Add discovery workshop, advisory days, report or deliverable milestone, monthly retainer and reimbursable expenses; show tax, deposits and any approved variation as separate lines.
Set deposit or advance retainer for new clients, then Net 14 or Net 30 for approved work, send the invoice while the job is current, and follow the status until payment is recorded.
The document should make the commercial history obvious to both independent consultants and advisory firms and their customer.
Takeaway: The strongest invoice mirrors the accepted scope, proves which job it belongs to and leaves one unambiguous balance to pay.
Create the first invoice, save the client details and review the next billing period from your account. Compare plan limits before choosing Pro.
Start the 7-day trialIt should support fixed deliverables, day rates or a recurring monthly retainer with separately approved expenses, reusable customers and line items, tax calculation, clear payment terms, delivery status, partial-payment tracking and overdue reminders. A full accounting or dispatch suite is optional; the billing workflow is not.
Include both parties, a unique invoice number, issue and due dates, statement-of-work, purchase-order or engagement number and the billing period, and itemised charges such as discovery workshop, advisory days, report or deliverable milestone, monthly retainer and reimbursable expenses. Show tax, payments already received and the remaining balance separately.
Yes. InvoiceSonic works in a mobile browser and on iPhone and iPad, so you can create and send the invoice close to the work instead of batching it later.
Yes. Record payments against the invoice, keep the remaining balance visible and use sent, viewed, paid and overdue status to decide the next action.
No. InvoiceSonic does not take a percentage of the invoice. A third-party card processor may charge its own fee; bank transfer and supported local payment rails can provide a lower-cost option.
A useful billing system starts with an invoice the customer can verify. Set up the job details, agree the charging basis and check the balance before you automate follow-up.
Identify whether you are billing consulting days, an agreed deliverable or a retainer period. Define the approval point for milestone work and how authorised expenses are handled. Avoid mixing a fixed deliverable fee with the same time already included in that fee.
Include the engagement name, statement-of-work reference, billing period and purchase order. Check the legal billing name and delivery contact against the accepted work. Keep the accepted statement of work, approved timesheet or milestone acceptance, and expense approval available to resolve questions. An invoice records the charge; it does not replace the underlying approval or supporting documents.
This engagement bills three days at the agreed rate plus an authorised expense. For a milestone engagement, substitute the accepted milestone and fee. Specify the service period so the client can distinguish this bill from the next one.
| Description | Quantity | Rate | Amount |
|---|---|---|---|
| Advisory days — agreed engagement | 3 | 600.00 | 1,800.00 |
| Approved travel expense | 1 | 80.00 | 80.00 |
| Example subtotal | 1,880.00 | ||
Sending an invoice before checking procurement requirements can delay approval even when the work is accepted. Ask for vendor setup, purchase-order and submission requirements before the first billing date.
When following up, identify whether the delay is approval, missing information or payment processing. Send the specific document needed rather than repeatedly issuing new invoices. Track the original balance until funds are recorded.
The free browser tool prepares the document. Saving customers, sending tracked invoices and managing reminders require an account and are subject to plan limits. Payment status needs accurate payment records; an invoice view alone does not confirm payment.
Reuse the billing contact and engagement reference, then review days worked, milestones or the retainer period. Track what remains unpaid after recording confirmed payments.
A September advisory retainer and an approved travel expense belong on separate lines. Include the purchase order if the client uses one for approval.
A free account includes 3 saved invoices, 1 tracked send and 1 automatic reminder per month. Pro adds recurring invoice preparation and higher usage limits. Review each generated invoice before sending; payments must be confirmed and recorded.