Professional services—law, accounting, consulting—have unique billing needs. Hourly work, retainers, trust accounts, and client expectations all create complexity. Here's how to handle it.
Common Billing Models
Hourly Billing
The traditional model: track time, bill for hours worked. Simple in concept, complex in practice. Requires accurate time tracking and clear communication about rates.
Best practices:
- Track time contemporaneously (not from memory later)
- Use consistent increments (6-minute, 15-minute, etc.)
- Describe work clearly on invoices (not just "research" or "calls")
Flat Fee
A fixed price for defined scope. Provides certainty for clients and rewards efficiency for you. Works well for standardized services.
Best practices:
- Define scope precisely to avoid disputes
- Have a clear process for scope changes
- Price based on value and experience, not just estimated hours
Retainer
Client pays upfront for ongoing access or a commitment of time. Common for lawyers and consultants. Provides stable revenue and signals commitment.
Best practices:
- Bill retainers at the beginning of each period
- Be clear about what retainer covers vs. additional charges
- Replenish retainer when it runs low (for evergreen retainers)
Industry-Specific Considerations
For Lawyers
- Trust accounts: Understand rules about client funds vs. earned fees
- Detailed billing: Legal billing often requires extensive detail for litigation and insurance purposes
- Billing guidelines: Corporate clients may have specific billing requirements you must follow
For CPAs and Accountants
- Seasonal workload: Tax season creates billing spikes; structure pricing accordingly
- Annual engagements: Many clients are billed annually; consider monthly payment plans
- Bundled services: Combine tax prep, bookkeeping, and advisory for recurring revenue
For Consultants
- Project-based billing: Define milestones and tie payments to deliverables
- Travel and expenses: Have clear policies on what's reimbursable
- Value-based pricing: Consider pricing based on outcomes, not just time
Collecting Payment
Professional services often have longer payment cycles. Strategies to improve collection:
Bill Promptly
Don't wait until month-end or quarter-end. Bill as work is completed or on a regular schedule.
Require Payment Methods on File
At engagement, collect a card that can be charged. For larger matters, automate monthly billing to the saved card.
Use Clear Payment Terms
Net 15 or Net 30 are common, but be explicit. Consider early payment discounts for large engagements.
Follow Up Professionally
Overdue invoices happen. Have a standard process: reminder email, phone call, escalation. Keep it professional—these are often long-term relationships.
Technology for Professional Services Billing
Traditional practice management software often includes billing. But for firms that want to use Stripe for payment processing, a billing portal like Conto provides:
- Professional invoicing through your Stripe account
- Saved payment methods for easy charging
- Recurring subscriptions for retainer billing
- Team access for staff who handle billing
The key is matching your billing tools to your practice's needs—and making payment as easy as possible for clients.