Professional Services Merchant Account

A professional services merchant account gives law firms, accounting practices, consulting firms, financial advisors, and marketing agencies the payment infrastructure to handle high-value invoices, recurring retainer billing, and B2B payment processing with full cost transparency. Brookside provides transparent pricing and dedicated support to help firms control — or eliminate — processing costs. According to Federal Reserve interchange fee data, most professional services firms overpay significantly on large invoices by defaulting to flat-rate pricing.

Professional services firms are increasingly choosing between two structures depending on whether they want to absorb processing costs or pass them to clients.

Dual Pricing: Offset Processing Cost Entirely

Dual pricing presents a cash/check price and a card price — the client who pays by card covers the processing cost. For a consulting payment processing scenario involving a $10,000 invoice, that’s roughly $250–$300 in processing cost that shifts to the client rather than being absorbed by the firm. It is permitted in all 50 states and works particularly well for firms where clients are accustomed to being billed for all engagement-related costs. Use our pricing model comparison to see the full picture alongside surcharge and cash discount program alternatives.

Interchange-Plus: Full Transparency, Lowest Absorbed Cost

For firms that absorb processing costs, interchange-plus pricing is the most cost-effective structure. Invoices of $5,000–$50,000 are common in professional services. At these amounts, the difference between a 2.9% flat rate and a 2.2% interchange-plus effective rate is $35–$350 per transaction. For a firm collecting six to twelve major invoices per month, the annual savings from a properly structured professional services merchant account can easily reach $10,000–$25,000.

Level 2/3 Data: Additional Savings on B2B Cards

Corporate and purchasing cards with Level 2 and Level 3 billing data can qualify for interchange rates 0.5–1.0% lower than standard card-not-present rates — a meaningful additional reduction for B2B-heavy firms. For why tiered and flat-rate pricing consistently cost more, see how tiered pricing works.

• Dual pricing and interchange-plus options — choose what fits your practice
• Invoice payment links and virtual terminal for remote collections
• Card-on-file and recurring billing for retainer arrangements
• Fast funding — often 1–2 business days
• Dedicated support — a real person who knows your account

Invoice-Based and Recurring Billing

Professional services firms frequently store client cards for recurring retainer billing or post-service invoice collection. Properly structured card-on-file and recurring billing arrangements qualify for lower interchange rates than one-off card-not-present transactions. Ensuring your processor supports Level 2 and Level 3 data for B2B card transactions is worth reviewing — corporate and purchasing cards with enhanced billing data qualify at meaningfully lower rates. For large invoices paid via bank transfer, ACH payment processing costs a flat fee of $0.20–$1.50 per transaction regardless of amount — often the lowest-cost option for invoices above $5,000. See CFPB guidance on card payments for consumer protection context on B2B card transactions.

Law Firm Trust Accounting Compliance

Law firm merchant services require special attention to trust accounting. Law firms and certain other professional services firms handling client trust funds must ensure their payment processing does not commingle trust and operating accounts. Proper merchant account configuration keeps processing fees from being deducted from trust account deposits — a compliance requirement in most state bar jurisdictions. Brookside reviews this during onboarding and configures accounts accordingly.

Switching Processors and Evaluating Your Current Costs

Most professional services firms that haven’t reviewed their processing in the past two years are overpaying. Our post on interchange fees explained breaks down what each card type actually costs. The bank merchant services call post explains why your existing banking relationship is rarely the best option for a professional services merchant account. When you’re ready to move, read how to switch payment processors without losing a day of collections. If you’re unsure whether a dedicated account makes sense at your volume, read do I need a merchant account.

Frequently Asked Questions

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See What Your Firm Should Actually Be Paying

Send us your last processing statement — one page is enough — and we’ll show you what interchange-plus pricing would cost at your billing volume and average ticket size. Most professional services firms we review (law, accounting, consulting) are paying 2.6%–2.9% on flat-rate when their interchange-plus rate would be 30–60 basis points lower. If the numbers don’t work in your favor, we’ll tell you that too.

No obligation • No pressure • Response within one business day