How Should an Accounting Firm Bill Clients: Per Return, Monthly or Up Front?

Which clients fit which billing model

Pick the model per client from last season’s billing export, by client ID: services, fee, invoice dates, days from invoice to payment, and write-offs. Then sort:

• Recurring work every month or quarter — bookkeeping, payroll, quarterly estimates, advisory: a monthly fee on autopay.
• One return a year with a known scope: per return, with a deposit at signing and the balance at delivery.
• Work whose size is unknown at intake — unfiled years, a cleanup, a first-year entity: a scoping fee, then a deposit and a fee per year or per phase.
• Any client who paid late last season, whatever the model: a deposit and a payment method on file before work starts.

Write the model into each client’s letter for the coming season, so the first invoice under it is not a surprise.

Moving clients to monthly autopay: what the letter and the authorization say

Autopay is where a federal rule applies. Regulation E covers transfers from a consumer “account,” which 12 CFR 1005.2 defines as a checking, savings or other consumer asset account “established primarily for personal, family, or household purposes,” and it defines a preauthorized transfer as one “authorized in advance to recur at substantially regular intervals.” A monthly debit from an individual client’s checking account fits. A company’s operating account falls outside that definition; there the firm’s payment processor and bank set the terms, so ask the processor what authorization it requires.

For consumer accounts, 12 CFR 1005.10(b) says preauthorized transfers “may be authorized only by a writing signed or similarly authenticated by the consumer,” and whoever obtains the authorization gives the consumer a copy. The official interpretation adds that an e-signature complying with the E-SIGN Act meets the signing requirement, that staff cannot sign for a client on the strength of a phone call, and that an authorization is valid if it is “readily identifiable as such” and its terms are “clear and readily understandable.” Under 1005.10(d), a debit that varies from the last one or from the authorized amount needs written notice of the amount and date at least 10 days ahead, unless the client chose notice only outside an agreed range; a fixed monthly amount avoids that. Under 1005.10(c), the client can stop a preauthorized transfer by telling the bank at least three business days before it is scheduled. Counsel confirms how this applies to the firm’s processor and form. The letter for a monthly client then says:

• The scope the fee covers, in units: entities, returns by jurisdiction, months of books, and whether notices are included.
• What is billed outside the fee, and at what price or rate.
• The debit date and amount, the date each year the fee is reviewed, and the notice before a new amount.
• What happens after a failed or stopped debit: how many days until work pauses, and who calls the client.
• What is owed if the plan ends mid-year: the work delivered, less the payments made. This clause protects a return finished in March and paid for in twelve parts.
• Which payments pay for which return or service, so a later question about fees due for a specific return has an answer.

Accounting firm client onboarding: the order before any work starts

The order is the control. When the portal invite goes out with the letter, documents pull work forward before anything is signed or paid. Five steps, in this order, owned by one administrator rather than a preparer:

• Scope and billing model confirmed in writing.
• Engagement letter signed, with the payment terms inside it, not in a separate fee schedule nobody signs.
• Payment method on file: the signed autopay authorization, copied to the client, for monthly clients; a card or bank account for deposit-and-balance clients.
• Deposit collected, where the model has one, with the payment link in the same message as the signature request.
• Then the portal invite, the organizer and the document request. Where the work needs the client’s IRS records, such as transcripts, the signed IRS authorization comes before the request. Form 8821, for example, lets a designee inspect or receive the client’s confidential information for the type of tax and the years or periods listed on it; which form fits is the preparer’s call.

A job that skips a step goes on the weekly list at the end of this guide, with the skipped step next to it.

New tax clients with unfiled years: a deposit, then one year at a time

Unfiled years are where a per-return fee quoted at intake is a guess: nobody yet knows how many years are open or what records exist. The IRS wage and income transcript shows information returns it received, such as Forms W-2, 1098, 1099 and 5498, for the current and nine prior tax years, and it “may not reflect all the information return documents issued to you.” The IRS page on past-due returns points to Form 4506-T for that information.

So price the work in two steps. First, a fixed scoping fee or deposit for the authorization, the transcripts, a list of open years and missing documents, and a written quote per year. Then a deposit for the first block of years, with each year’s return released when that year is paid. How many years to file, and in what order, is the preparer’s judgment and the client’s decision. The quote holds:

• Each year in scope, priced, and what adds a year.
• The scoping fee or deposit, and whether it is credited to the returns.
• The order of delivery, and the payment due before each year’s return is released.
• What happens if payments stop partway: which years are finished, what the firm holds, and what goes back to the client under the records rules below.

One IRS line belongs in the fee conversation: it holds income tax refunds “in cases where our records show that one or more income tax returns are past due,” until it gets those returns or an acceptable reason for not filing. A fee planned around the first refund may end up waiting on the other open years too.

When a client never pays: the steps, and what a firm may hold back

Whether the debits stopped or a per-return invoice is months old, the steps are the same: a written schedule — reminder, call, partner letter, final notice — owned by one person. The letter’s terms decide what pauses: new work, monthly services, and next season’s letter until the balance is paid or a plan is agreed. Then a written, dated decision: a payment plan, small claims, an attorney, a collection agency, or a write-off.

Two sets of rules limit what goes out with the account. The AICPA Code’s confidentiality rule says a member in public practice “shall not disclose any confidential client information without the specific consent of the client,” and interpretation 1.700.070 says the rule “is not intended to prohibit” disclosing information necessary to “initiate, pursue, or defend the member” in an actual or threatened lawsuit or alternative dispute resolution proceeding. For tax return information, 26 CFR 301.7216-2(l) lets a preparer use and disclose what the taxpayer gave to pay for the services “to the extent necessary to process or collect the payment”; anything else needs the taxpayer’s prior written consent unless another provision of that section allows it. What a collection agency may receive is a question for the firm’s attorney before the account goes out.

Holding back is narrower than an unpaid invoice suggests. The AICPA’s Records Requests interpretation, ET 1.400.200, which binds AICPA members, sorts records into four kinds:

• Client-provided records, the client’s own documents: made available on request. The firm may charge a reasonable fee to retrieve, copy and ship them, but they “may not be withheld for nonpayment of such fees.”
• Member’s work products, the work the terms of the engagement call for, “such as tax returns”: may be withheld if fees are due for that specific work product, if it is incomplete, to comply with professional standards, or where litigation about the engagement is threatened or outstanding.
• Member-prepared records, such as adjusting or closing entries the firm proposed that are not in the client’s books: made available when they relate to a completed and issued work product, unless fees are due for that work product.
• Working papers: the firm’s property, which it is not required to make available, though statutes, regulations and contracts may add requirements.

The interpretation asks for compliance as soon as practicable and, absent extenuating circumstances, within 45 days of the request. A stricter state board rule controls — a board “may not permit a member to withhold certain records, even though fees are due” — and a state lien statute does not change the obligation. For practitioners before the IRS, 31 CFR 10.28 says the client’s records needed for federal tax obligations go back promptly on request, and a fee dispute generally does not change that, with a narrower rule where state law allows retention. Its definition of the client’s records excludes a return the practitioner prepared if it is withheld “pending the client’s performance of its contractual obligation to pay fees with respect to such document.” Both texts tie holding back a finished return to fees due for that return, which is why the letter should say what each payment pays for. How either applies to a dispute is for the firm’s attorney or ethics counsel. Not legal advice.

What to check weekly, and when this needs no outside help

One owner, one weekly pull from billing and practice management, by client ID: receivables by age, oldest first; debits that failed or were stopped; documents uploaded with no signed letter; signed letters with no payment method or deposit; and unfiled-years work running ahead of its payments. A list that grows two weeks running goes to a partner.

A firm with a short client list, a partner who knows every balance, and billing models already in signed letters does not need anyone to run this. An outside review earns its fee when billing is one leak among several and the records do not connect. The Revenue Review takes two weeks. It reads the firm’s own billing and practice-management exports, read-only — counts, dates and stages with client IDs, never returns or workpapers — and prices each gap where the records support a number. It writes no client letters, sets no fees and gives no tax, legal or ethics advice.

If it is unclear whether any of this is worth a fee, the next step is a free 20-minute call, where a firm too small for the arithmetic is told so.