Best Payment Plan Software for Tax Preparers: 5 Tools, 2027

Key Takeaways

• A tax fee "payment plan" can mean two things: scheduled client charges, or a model where the firm is paid in full up front. Decide which one you need before you compare tools.

• Stripe is the only tool in this set whose documentation shows a fixed installment count that ends on its own, but it requires API work.

• QuickFee's page describes client installments with the firm paid up front, but it publishes no prices and no term schedule.

• Karbon's Team plan costs $59 per user a month on annual billing, and its page does not describe installment schedules.

• PaySimple's single plan costs $79.95 a month, and Ignition's pricing page did not show its tier prices when checked on October 28, 2026.

• On the published card rates shown here, six $200 charges cost $36.60 with PaySimple or Stripe.

The decision comes before the tool

A payment plan for a tax fee is a schedule that splits one engagement fee into dated client charges, and the central choice is who carries the unpaid balance.

If the firm carries the balance, you need a tool that charges on a fixed schedule, stops on its own, and flags failed payments quickly. If the firm wants to be paid in full up front while clients pay over time, you are buying a financing-style product, and its terms deserve a close read before you sign. If you already run a practice platform, check its recurring billing before buying a second tool, because a recurring charge that never ends is not an installment plan.

Firms are collecting more money before work starts. Upfront deposits: 31% in 2025, up from 26% in 2024 according to Accounting Today (2025). That survey covered 219 U.S. accounting firms and was run by Ignition, a vendor covered in this guide, and every firm in the sample used Ignition's software, so read it as directional. The article does not discuss installment plans, so it supports the upfront side of the decision, not the schedule side.

TL;DR: pick the fee model first. Stripe and PaySimple handle recurring charges, QuickFee handles client-facing installments with the firm paid up front, and Karbon and Ignition are practice systems whose plan features need checking before you buy.

How we evaluated these tools

The weights below are our judgment for a small tax practice, not vendor data. Installment mechanics carry the most weight, because a plan tool that cannot stop charging on schedule creates more work than it saves.

We scored five tools whose pages gave us enough to compare. Two others are not scored. TaxDome's pricing page returned an access error when checked on October 28, 2026, so we could not confirm its plan prices or payment features. EBizCharge's pricing page is quote-only and does not describe installment plans. We also did not score Canopy or Financial Cents, because our searches surfaced no installment-plan detail from either vendor.

What each tool documents

"Not described" means the page we opened does not say so. It does not mean the feature is absent. Ask each vendor in writing for schedule behavior, processor fees and the process for failed payments before you buy.

Pricing and fee math

Pricing checked October 28, 2026.

Team plan price: $59 per user a month, billed annually according to Karbon (2026). Monthly billing is offered only to teams of four or more. The Team plan caps contacts at 1,000 and work templates at 40, according to Karbon (2026).

Stripe's Billing pay-as-you-go rate is 0.7% of billing volume with no recurring fee, card processing is 2.9% + 30¢ per successful card charge, and ACH direct debit is 0.8% with a $5.00 cap, according to Stripe (2026). The 0.7% is a separate Billing charge, not part of card processing, so budget for both if you use Billing.

QuickFee's page publishes no prices, fee schedule or interest rate, so its row reads Quote-based. Ignition's pricing page showed a free trial and monthly and annual toggles, but tier prices did not load in the captured text, so its row says so rather than guessing.

The table restates figures from the pages cited in this article. Card and ACH columns apply each published rate to six $200 charges, and the PaySimple card figure uses its "as low as" starting rate, so treat it as a floor.

Here is one illustrative case, not a real customer. A firm bills a $1,200 tax preparation fee as six monthly payments of $200 through Stripe. Stripe's documentation shows this pattern as a subscription schedule with the installment count set in iterations and end_behavior set to cancel, so the subscription ends after the sixth charge. At the 2.9% + 30¢ card rate, each $200 charge costs $6.10 ($5.80 plus $0.30), so six charges cost $36.60, or 3.05% of the fee. If the firm absorbs that cost rather than passing it to the client, it keeps $1,163.40. On ACH at 0.8%, the same six charges cost $9.60 in total. Those totals exclude the 0.7% Billing rate, which would add $8.40 on a $1,200 fee.

Vendor profiles

Facts in each profile come from the vendor page cited. "Best fit" and "Limitations" are our read.

Karbon

Best fit: a firm that already runs Karbon for workflow and wants payments, billing and client reminders on one platform.

Evidence: the pricing page lists payments as a Team feature and "Auto-payments" in its comparison table, and it places automatic client reminders on the Business plan rather than Team.

Limitations: the page does not describe installment schedules, so a fixed payment plan would need to be confirmed or built. The Team plan's 1,000-contact cap matters for larger client lists.

Implementation: Karbon is a platform purchase, so the work is configuration. Ask for written confirmation of how one engagement fee can be split into a set number of charges, and who sees a failed charge.

PaySimple

Best fit: a firm that wants one fixed price for recurring card and ACH charges and a simple monthly bill.

Evidence: PaySimple's single plan: $79.95 a month according to PaySimple (2026). The same page describes recurring payments and automatic billing, and it says volume over $50,000 a month gets a custom quote.

Limitations: annual pricing is not published, and the pricing page refers to billing schedules without saying whether a fixed installment count is supported. Card processing is "as low as" 2.90%, so your real rate depends on your mix of cards.

Implementation: before signing, confirm in writing that a schedule ends after a set count and that a failed charge routes to a named person at the firm.

Stripe

Best fit: a firm with a developer or an agency partner that needs a fixed installment count and wants to own the data flow.

How the installment works: Stripe's documentation says the iterations count is multiplied by the price interval, so six monthly iterations means six monthly charges, and end_behavior set to cancel ends the subscription after the last one, according to Stripe (2026).

Limitations: the installment examples are API calls, and the dashboard steps describe phases by duration, so plan on code. Stripe does not provide a tax-practice client portal, engagement letters or intake, so the fee policy sits outside the tool.

Implementation: Stripe's event list includes a subscription_schedule.completed webhook that fires when a subscription schedule is completed, so a workflow can close a matching fee record when that happens.

QuickFee

Best fit: a firm that wants to offer clients a pay-over-time option while the firm is paid in full up front.

Evidence: the page says clients can split invoices into installments by ACH or card. Its testimonials mention a "3 or 6-month option" and a 12-month plan, but the page publishes no term schedule. According to QuickFee (2026), the firm gets paid in full whichever option the client picks.

Limitations: the page publishes no prices, fee schedule or interest rate, and testimonials describe "nominal" interest and fees without figures. Ask who carries credit risk, what happens when a client stops paying, and what the firm pays for each plan.

Implementation: QuickFee creates a payment link for the firm within a few days, and the firm can add it to invoices or its website.

Ignition

Best fit: a firm that wants practice management and billing in one place, with recurring retainers and one-off project billing.

Evidence: Ignition's comparison page describes a 14-day free trial, a flat monthly subscription with a discount for annual payment, and payment transaction fees when a firm uses Ignition payments, according to Ignition (2026). Its product page says recurring billing covers retainers and one-off billing covers projects, and it names direct QuickBooks Online and Xero integrations, according to Ignition (2026).

Limitations: neither page describes installment schedules, and the product page does not mention an API. Tier prices did not appear in our capture, so get current tiers before you budget.

Implementation: the QuickBooks Online and Xero integrations are direct, so confirm during setup which firm-side steps connect the ledger and who reviews a sync error.

Build it yourself with Zapier, Make, n8n or code

Many firms will compare these tools with a workflow built in Zapier, Make or n8n, or with in-house code, and that route deserves a fair hearing. Those tools can keep run histories, retries, error branches and audit logs when they are configured for it.

The cost of that route is ownership. The firm must design and maintain idempotency, so a retried webhook does not create a second charge. It must define escalation when a payment fails, control access to client bank and card data, and keep the workflow working when a practice system changes its API.

For a firm with one technical person, a build against Stripe can be the lowest-cost route, and the real cost is ongoing maintenance rather than a license. For a firm with no one to maintain code, a packaged product with a documented schedule feature is usually the lower-risk choice.

Where a proposed US Tech Automations design fits

The workflows below are proposed and configurable. They are not a deployed system and do not describe any firm's results. US Tech Automations would configure them on top of whichever tool the firm chooses.

Proposed workflow one covers fee schedule setup. The trigger is an engagement fee marked approved in the practice system. The prerequisites are an API or scheduled CSV export of client, engagement and fee fields, plus a stored link between each client and its processor customer record. The action drafts an installment schedule using the count and amount the owner sets, then creates it in the processor using the subscription schedule pattern described above. The output is a schedule summary written back to the engagement record. The human review point is that the owner approves the schedule before the first charge is created.

Proposed workflow two covers failed-payment follow-up. The trigger is a webhook from the processor reporting a failed installment. The prerequisites are webhook access on the processor and a task API in the practice system. The action drafts a reminder to the client and opens a task with a due date for staff. The output is a task and a log entry. The review point is that staff approve every client message, and nothing in the workflow edits a schedule or waives a balance without a person deciding.

Proposed workflow three covers schedule close-out. The trigger is subscription_schedule.completed, which Stripe sends when a subscription schedule is completed. The prerequisite is the stored schedule ID from the setup step, which Stripe's documentation advises keeping alongside the subscription ID. The action closes the matching fee record and archives the schedule ID. The review point is a monthly reconciliation of collected payments against each schedule, completed by a person, because a workflow can match records but cannot judge a dispute.

The difference from a plain platform is the orchestration layer. The proposed design ties the fee record, the processor schedule and the staff task together and keeps the human approvals explicit. It does not replace the processor or the practice system, and a firm with no API access and no plan for review should not start there.

Who should pick which tool

Who this is for

This is for owners and operations leads at small tax practices who want clients to pay engagement fees in installments without manual chasing. Choose from the fee model you decided on, not from the feature list.

Red flags: you need installments inside a tax client portal with no custom work; no one at the firm will own failed-payment follow-up; or the firm would carry client credit risk without a written fee policy.

Who should choose each tool

• Karbon: a firm already on Karbon that wants payments and reminders in the same workflow tool.

• PaySimple: a firm that wants one fixed price and recurring card and ACH charges, and can confirm installment behavior before signing.

• Stripe: a firm with a developer or agency that needs a fixed installment count and will own the code.

• QuickFee: a firm that wants clients to pick a pay-over-time option while the firm is paid in full up front, after reading the financing terms.

• Ignition: a firm that wants practice management and recurring retainers in one place and works in QuickBooks Online or Xero.

When NOT to use US Tech Automations

A proposed US Tech Automations design is the wrong choice in three situations. If the firm sends only a handful of invoices a year, the card link in an existing practice system is simpler and leaves no workflow to maintain. If the firm already runs Karbon or Ignition and its recurring billing covers fixed-fee retainers, a second layer adds steps without adding a payment rule. If the client needs an IRS installment agreement, that runs through the IRS's own online system, and no fee workflow changes its terms.

Decision checklist

1. Write down the fee model: the firm carries the balance, or the firm is paid in full up front.

2. Set the number of installments and the charge frequency your clients need.

3. Confirm the tool stops charging on its own after the last installment.

4. Get plan prices and processing fees in writing, with a date.

5. Name the accounting integration you need and confirm it in writing.

6. Name the person who handles failed charges and the steps they follow.

Common mistakes to avoid

• Treating recurring billing as an installment plan. A recurring charge that never ends is not a plan.

• Comparing processing rates without counting charges. Per-charge fees add up on small installments, as the six-charge example above shows.

• Assuming an IRS payment plan covers your engagement fee. An IRS agreement is between the taxpayer and the IRS, not the preparer's fee.

• Leaving failed payments with no owner.

• Skipping a written fee policy that says what happens if a client stops paying.

Common questions

Is recurring billing the same as a payment plan?

No. Recurring billing repeats a charge until someone cancels it, while a payment plan should end after a set number of installments, so check that the tool stops on its own.

Who should carry the unpaid balance?

The firm carries it unless the product you choose pays the firm up front, and that choice should be written into the engagement terms before billing starts.

Can a preparer set up an IRS payment plan for a client?

Only with proper authority: the IRS requires a Tax Pro Account or a Form 2848 before a representative applies, and its simple payment plan covers balances of $50,000 or less, according to IRS (2026). That plan is a tax-debt agreement, not your engagement fee.

Do these tools add a fee on top of card processing?

Some do: Stripe's Billing rate of 0.7% of billing volume is separate from its card rate, and Ignition's page says it charges transaction fees when a firm uses its payments. Confirm whether any platform charge applies before you compare totals.

Which tool suits a firm with no developer?

Stripe needs API work for installments, so a firm with no developer should start with a packaged tool such as Karbon, PaySimple, Ignition or QuickFee, and confirm the installment behavior in writing.

Why are some prices missing from this comparison?

This guide prints only prices read on the vendor's own page. QuickFee publishes none, and Ignition's tier prices did not load when checked, so those rows say so rather than estimating.

Bottom line

Pick the fee model first. If the firm needs a fixed installment count that ends on its own, Stripe is the only tool here whose documentation shows that mechanism, and it requires code. If you want clients to choose a pay-over-time option while the firm is paid up front, QuickFee fits that model, and its terms need a written review before you rely on them. If you already use Karbon or Ignition, check their recurring billing before buying a second tool. For a firm that wants a proposed design with explicit review points, see how US Tech Automations configures this.