A retainer is not a coffee purchase with more zeroes.
Professional firms collect a small number of large payments, often from commercial cards or stored credentials. Percentage-heavy markup grows with the invoice even when the operational work does not.
Target markup, never a promise or guarantee · Final pricing and approval are determined by underwriting
The billing method needs to survive professional obligations
Trust and operating money may need separate treatment. Legal practices should confirm that deposits, processing deductions and chargebacks are routed in a way that complies with their jurisdiction's trust-account rules.
Do not assume a generic checkout is suitable. The processor must confirm the account configuration, and the firm should obtain advice from its own legal and accounting professionals. Pcnaid is a referral partner, not a law firm, bank or payment processor.
A retainer month, calculated as keyed or online payments
This example uses card-not-present mode because retainers are frequently paid through invoice links, stored credentials or keyed entry rather than at a terminal.
Monthly client-card volume
The amount used for this worked example.
Average payment
The calculator derives 25 transactions from this amount.
This account's target markup and fees
Computed from the current pricing model.
Dharma
$0/mo + 15 bps + 11¢/txn
Modeled monthly difference
Annualized at unchanged activity: $1,218.00.
The result is an estimate, not a quoted saving. The account's markup is a target, never a promise or guarantee. The processor's underwriting department reviews the firm and sets final pricing.
This compares processor markup and monthly fees only. Interchange and card-brand assessments are set by the card networks, apply equally to all providers, and are not included.
Commercial cards change the base cost, not the argument
Corporate and rewards cards can carry higher interchange than consumer debit. Interchange-plus pricing does not remove that cost; it shows the network amount separately from processor markup.
Retainers
Large, occasional payments make the percentage component of markup easy to see. Document client authorization and the purpose of the payment before charging the card.
Recurring invoices
A stored credential is generally card-not-present. Consent, cancellation terms and accurate descriptors help the client recognize the charge and reduce avoidable disputes.
Commercial-card data
Some business-card transactions may qualify differently when additional invoice data is supplied. Confirm supported fields and workflow with the processor before relying on that treatment.
When flat rate is actually better
A solo adviser who normally receives checks or bank transfers and accepts only a handful of card payments each year may prefer a flat-rate payment link. Minimal setup can matter more than optimizing rare transactions.
A firm collecting retainers or recurring balances every month has a different decision. Consistent large tickets make the percentage component worth separating from interchange.
Questions before accepting a retainer
Can a disputed retainer lead to held funds?
Yes. A high-value dispute can trigger review by the processor or acquiring bank. Pcnaid does not control risk or funding and cannot promise that funds will never be held.
Is the target markup guaranteed for a professional firm?
No. It is never a promise or guarantee. The processor’s underwriting department determines approval and final pricing after reviewing the firm’s application and payment activity.
Who configures trust-account routing?
The support front line is an AI voice agent that triages the request and routes it to onboarding or technical support. The processor must confirm the available configuration; the firm remains responsible for professional-rule compliance.
Price the way clients actually pay.
Use the average card payment rather than the face value of every invoice, and choose card-not-present mode when retainers arrive through links or stored credentials.
Applying carries no obligation. Underwriting, approval and final rates are determined by the processor.
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