Invoicing Software for Professional Services Businesses
Send professional invoices for retainers, projects, and hourly work — bill U.S. clients with the right Sales Tax applied, and international clients in their own currency. Built for consultants, agencies, accountants, and every professional services firm that bills by the hour or the project.
What Is Invoicing Software for Professional Services Businesses?
Professional services invoicing software turns a proposal or scope of work into a billable engagement — tracking retainers, milestones, and hourly work under one client record, then converting that into a professional invoice. BillNama applies the correct Sales Tax automatically wherever your services are taxable, bills international clients in their own currency, and lets you send the invoice by email, PDF, or WhatsApp the moment an engagement wraps.
Proposal vs. invoice: a proposal or scope of work sets the terms before you start; an invoice is what you bill once the work — or a milestone of it — is delivered. BillNama lets a client approve a quote and converts it into an invoice with one tap.
Everything Your Professional Services Firm Needs
From the first proposal to the final payment, BillNama keeps every client, engagement, and invoice in one place.
Retainer & Milestone Billing
Bill monthly retainers automatically, or invoice a project milestone the moment it’s delivered.
Hourly & Project-Based Invoices
List hours, deliverables, or project fees as separate line items so every invoice matches the engagement.
Professional Invoice Templates
Dozens of ready-made layouts. Add your logo and brand colors so every invoice looks like it came from your firm.
Automatic Sales Tax Calculation
Set your state once. BillNama applies the correct Sales Tax on every invoice, wherever your services are taxable.
Multi-Currency Billing
Bill international clients in 160+ currencies, with the right symbol and formatting applied automatically.
Get Paid Faster
Share a payment link so clients pay directly, and see the moment an invoice is viewed and paid.
From Proposal to Payment in 3 Steps
Quote the Engagement
Send a client a quote for the retainer, project, or hourly scope before work begins.
Bill the Work
Convert an approved quote into an invoice, or bill hours and milestones as the engagement progresses.
Get Paid & Track
Share a payment link, and see exactly what’s been billed, collected, and still owed per client.
Built for Every Professional Services Firm
Consultants & Agencies
Handle retainers, milestones, and multi-currency clients from one account.
Accountants & Bookkeepers
Bill clients on a recurring schedule and keep every invoice tax-compliant.
Legal Services
Invoice by the hour or the matter, with a clean, professional layout clients trust.
Marketing & Advertising Agencies
Bill monthly retainers and one-off campaigns from the same client record.
IT & Tech Consultants
Invoice project work and support retainers, and bill international clients correctly.
Financial & Insurance Advisors
Send recurring advisory invoices and one-time service fees without spreadsheets.
More Than Invoicing — Run Your Whole Practice
Professional Services invoicing connects directly to the rest of BillNama, so a quote, an engagement, and a payment all live under the same client record.
Multi-Currency InvoicesBill international clients correctly
Quotations & EstimatesProposals clients can approve into invoices
Recurring InvoicesAutomate retainers & subscription billing
Customer LedgerEvery client’s full balance & history
ExpensesTrack costs against related engagements
Send Invoice on WhatsAppReach clients where they reply fastest
Invoice SignaturesGet sign-off directly on the invoice
Reports & EarningsWhat you’ve billed, collected & are owed
GST InvoicesCGST/SGST/IGST & HSN/SAC handled
VAT InvoiceUK, EU & Gulf VAT formats built in
Proforma InvoicesConfirm an engagement before you bill it
Why Professional Services Firms Choose BillNama
- Retainers, milestones, and hourly work billed from one place
- Sales Tax calculates itself, so invoices stay state-correct
- Every client, engagement, and payment synced across iOS, Android, and web
- Free forever plan — no card required to send your first invoice
Frequently Asked Questions
What is the best invoicing software for professional services businesses?
The best invoicing software for professional services lets you quote an engagement, bill retainers or milestones as work progresses, and collect payment without chasing clients. BillNama does all three from one app, and calculates Sales Tax automatically wherever it applies.
Does BillNama calculate Sales Tax for professional services invoices?
Yes. Set your business state and BillNama applies the correct Sales Tax automatically, wherever your services are taxable — tax rules for professional services vary by state, and BillNama keeps your invoices compliant either way. GST and VAT are supported too for international clients.
Can I bill clients on a retainer?
Yes. Set a billing interval — weekly, monthly, or custom — and BillNama generates and sends the retainer invoice automatically on schedule.
Can I send a proposal or quote and convert it into an invoice?
Yes. Send a client a quote for the engagement, and once they approve it, convert it into an invoice in one tap — no re-entering scope, rates, or client details.
Is BillNama’s invoicing software free for professional services businesses?
Yes. BillNama’s free forever plan lets you create up to 2 invoices a month with no credit card required. Paid plans remove that limit and add features like team access and advanced reporting.
Can I invoice for hourly work and project fees separately?
Yes. Add hours, deliverables, or flat project fees as separate line items on the same invoice, so clients can see exactly what they’re paying for.
Can clients pay an invoice online?
Yes. Invoices can include a payment link so clients pay directly, and you can see the moment an invoice is viewed and paid.
Can I bill international clients in their own currency?
Yes. BillNama supports 160+ currencies, so consultants and agencies can bill international clients in their local currency without manual conversion.
Can I send invoices through WhatsApp?
Yes. BillNama can send the full invoice, including a pay-online link, directly through WhatsApp instead of email.
Can I customize my invoice with my firm’s logo and branding?
Yes. Add your logo, choose your brand colors, and pick from dozens of templates, so every invoice looks like it came from your firm.
Can I create GST or VAT invoices if I also work with international clients?
Yes. Set the client’s country and BillNama applies GST (India) or VAT (UK/EU/Gulf) automatically, alongside your standard U.S. Sales Tax invoices.
Which professional services firms can use BillNama?
Consultants, agencies, accountants, bookkeepers, law firms, marketing and advertising agencies, IT and tech consultants, financial and insurance advisors, architects, engineers, and coaches all use BillNama to quote, invoice, and get paid.
Ready to Simplify Your Client Billing?
Join 38,000+ businesses using BillNama to bill clients, apply the right tax, and get paid faster — free forever.