What does AI proposal and engagement letter software cost for an accounting firm?

Four tools in this directory price the engagement, get the letter signed and collect the first payment, and all four post prices and offer a way to try them. Read in October 2026 from the Proposals, Pricing & Engagement Letters category.

The four, by price

• Socket: $13/mo on annual billing for up to 20 active clients (Starter); a Standard core membership is $33/mo for up to 100 clients, with modules such as Pro Features and Engage at $11–$20 each. Unlimited users and proposals on every plan, automated billing through Xero, 14-day trial. Socket AI builds a priced proposal from the discovery call. 2026 Xero Practice App of the Year (UK).
• FigsFlow: the US edition is free until February 28, 2027, then from $29/mo for Onboarding Solo, $79 for a team of three and $199 for a practice of 15; the full Practice Suite is $59 per person per month on annual billing. The AI Assistant suggests services and wording and triages email; a paid AI Assist seat arrives in January 2027.
• Ignition: Solo $39/mo on annual billing ($49 monthly) for up to 20 active clients, Core $99 ($149 monthly) for 50 clients and three users, Pro $229, Pro+ $399. Proposal, engagement letter, payment authorization and recurring billing in one signature; AI Price Insights benchmarks your prices (an annual add-on, included on Enterprise), AI drafts service descriptions, and the Ignition MCP opens the data to Claude and ChatGPT. 14-day trial with no card.
• Anchor: no subscription, $5 per payment received. Signed proposals become automatic invoices and ACH or card collection synced to the ledger; an MCP lets AI agents draft proposals, and Ping flags billing items that need attention.

Bundled elsewhere

Several practice platforms include proposals and e-signed engagement letters: SuiteDash ($19/mo), TaxDome ($800/user/yr), Canopy ($74/user/mo) and Paro (Contract Builder drafts SOWs; free plan). Liscio ($19/user/mo) handles e-signature in the portal. What the dedicated tools add is pricing — benchmarks, options and extras, price monitoring — and payment at signing.

Transaction fees

Ignition charges card and ACH fees when you collect through it (listed on its page); Anchor's $5 is the whole price; Socket bills through Xero or QuickBooks; FigsFlow uses Stripe or GoCardless.

Quick answers

What is the cheapest proposal and engagement letter tool for a solo accountant?

Socket at $13/mo on annual billing for up to 20 clients, or Anchor with no subscription at $5 per payment received. FigsFlow is free until February 28, 2027.

Which tool uses AI to suggest what to charge?

Ignition's AI Price Insights benchmarks your prices and suggests one with its reasoning (an annual add-on, included on Enterprise). Socket AI builds a priced proposal from the discovery call using your pricing menu.

Can these collect payment at signing?

Ignition takes payment details at signing and auto-bills recurring work, Anchor turns the signed agreement into automatic invoices and collection, and Socket and FigsFlow bill through Xero, QuickBooks, Stripe or GoCardless.