Tax planning retainer vs one-time fee: which to sell

In the tax planning retainer vs one-time fee choice, sell a one-time plan when the owner has one or two decisions to make, and a retainer when their plan needs action at three or more points in the year. Count those dated actions from the IRS calendar, price each option as a fixed fee for a written scope, and keep the fee separate from any savings figure.

That rule turns a pricing debate into a count. It also gives the owner a reason for the option you recommend that has nothing to do with your revenue.

Count the dated actions

List every action the owner's plan needs and put a date on each one. The IRS calendar supplies most of them.

Action	When	Source
Estimated payment, period 1	April 15	IRS estimated tax due dates
Estimated payment, period 2	June 15	same
Estimated payment, period 3	September 15	same
Estimated payment, period 4	January 15 of the next year	same
S corporation election (Form 2553)	No more than 2 months and 15 days after the start of the tax year it takes effect, or during the year before	IRS, instructions for Form 2553
Owner salary review	Before the next payroll change	IRS, S corporation compensation
Retirement contributions against 2026 limits	Through the year	IRS, 2026 limits
Year-end review	November to December	your own calendar

Then apply the rule:

One or two dated actions: a one-time plan, with a written summary and one review meeting.
Three or more: a retainer. The plan needs someone to check the numbers at each date, and a one-time plan leaves the owner to do that alone.

An owner with a single entity, steady income and one question about salary needs a plan. An owner with a growing S corporation, uneven quarterly profit and a retirement plan to fund needs someone at every estimated payment date.

What each option includes

	One-time plan	Year-round retainer
Written plan	Yes	Yes, updated during the year
Meetings	One review	One per quarter, plus year end
Estimated payment amounts	Set once	Checked before each due date
Questions between meetings	Not included	Included, within a stated limit
Implementation help	Not included, quoted separately	Agreed items included
Return preparation	Separate	Separate, or bundled at a stated fee

Write the "questions between meetings" limit down. "Up to two short email questions a month" is clear. "Ongoing support" invites scope creep.

See if your firm is a fit

Pricing a tax planning retainer vs one-time fee

Price each option as a fixed fee for a written scope. Fixed fees are easier for an owner to say yes to than an hourly estimate, and easier for you to deliver profitably if the scope is tight.

Two rules limit how you set the fee. Circular 230 section 10.27 says a practitioner may not charge an unconscionable fee in connection with any matter before the IRS, and it bars contingent fees outside narrow exceptions. It defines a contingent fee to include one "based on a percentage of the taxes saved," and it counts "tax planning and advice" as a matter before the IRS (31 CFR 10.27). So you can't price a retainer as "20% of what we save you," and you can't offer to refund the fee if a position is challenged.

Worked example (example numbers only, use your own): Your one-time plan takes 8 hours: 1 for the meeting, 5 for analysis, 2 for the written plan and review. Your retainer takes 8 hours to start, then 3 hours at each of four check-ins and 4 hours at year end, which is 24 hours in the year. If you price planning time at $250 an hour, the one-time plan is $2,000 and the retainer is $6,000 a year, or $500 a month. Check your own hours over three engagements before you fix the price.

Moving a one-time client to a retainer

A one-time plan can be a good way into a retainer. The owner sees your work, then has to act on it alone.

Book a short call two weeks before the next estimated payment date in the plan. Ask how the plan is going and whether the payment amount still fits. If the owner is unsure, that's the moment to offer the retainer, with the first check-in credited from the fee they've already paid if you choose.

Mistakes that cost firms money on planning fees

A retainer with no scope limit. Unlimited questions become unlimited hours.
Bundling prep in without a price. Owners stop seeing what planning costs.
Discounting the first year. The discount becomes the price.
Linking the fee to savings. It's a contingent fee under section 10.27.
No end date. Set a 12-month term with a renewal review.

What our marketing has taught us about planning offers

We run marketing that fills tax firms' calendars with qualified planning meetings. Two parts of our process connect to how firms price planning.

We check that the firm already sells paid planning. It's one of the things we need from a firm before we start, along with someone who runs planning meetings and room on the calendar.
The owners we book want proactive planning during the year. That's one of the written criteria. A retainer is built for exactly that kind of owner, one who wants planning through the year.

The firm sets its own fees and decides who to take on.

Where to start this week

Build the dated-action table above into your meeting template.
Write a fixed scope and fee for a one-time plan and for a retainer.
Set a written limit on questions between meetings in the retainer.
Check your proposals and site for any fee wording tied to savings and remove it.
Book a check-in call before the next estimated payment date for every one-time client.

Questions firm owners ask

Should I charge a retainer or a one-time fee for tax planning? Count the dated actions the owner's plan needs. One or two suits a one-time plan with a review. Three or more, such as estimated payments, a salary change and retirement funding, suits a year-round retainer.

How much should I charge for tax planning? Price each option as a fixed fee for a written scope, based on your own hours and rate. Check the hours over a few engagements before you fix the price. Don't tie the fee to the tax saved.

Can a tax planning retainer be based on the savings achieved? Circular 230 section 10.27 defines a fee based on a percentage of the taxes saved as a contingent fee and applies it to tax planning and advice. Outside narrow exceptions, practitioners may not charge contingent fees.

What should a tax planning retainer include? A written plan updated during the year, quarterly check-ins, estimated payment amounts checked before each due date, a stated limit on questions between meetings, a year-end review and a 12-month term.

Sources

General information from the official sources listed below, checked 25 Oct 2026. Not tax or legal advice.

If you'd rather have qualified owners booked for you

Financial Sales Insider is a marketing company for US CPA and EA-led tax firms. We fill your calendar with qualified tax planning meetings. Our marketing finds business owners who fit your criteria, qualifies them, and books them with you.

20 qualified tax planning meetings in 90 days, guaranteed.

If you have fewer than 20 qualified meetings after 90 days, we keep booking with no further monthly fee until you reach 20.

A qualified meeting is one where a business owner we've qualified books onto your calendar and shows up.

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Johnny Logan, Founder, Financial Sales Insider.

Financial Sales Insider · Florida · (305) 513-1710