Plumbmark
Flat-fee · No per-seat

The operations layer for one person, running a portfolio of clients like a firm twenty times her size.

Flat-fee, AI-first operations layer for solo accountants and small professional service firms. Portal, e‑sign, AI document intelligence, reminders, KYC/AML checklists, and invoicing — bundled for the solo accountant, bookkeeper, tax preparer, or small firm that today still stitches the same five tabs together.

Get early accessSee the problem

Starting around $99/mo flat — no per‑seat, no per‑document upsell, no "enterprise tier required."

This week · 14 clients
Live
Plumbmark is reading, drafting, and nagging — so you can do real work.
Open returns42vs 39 last wk
KYC gaps6auto‑flagged
Anomalies2needs review
ClientStageΔ
Reyes & Co.
Engagement letter · 3 docs
In review
+
Halloran LLC
946 imported, flagged
KYC gap
!
M. Tran, EA
Q1 close · packets 2/5
Close
+
Northbeam PC
1099-NEC queue · 6 vendors
Filing
Δ
What a solo operator stitches today

Five tabs. Five logins. One operator holding it all together.

Before there's a portal, a solo firm is duct‑taping QuickBooks, Stripe, DocuSign, Gmail, and a compliance checklist into a workflow that holds together only because one person remembers it. Plumbmark folds those tools into one operations layer.

  1. 01

    Client portal & e‑sign

    A secure upload + branded e‑signature surface — the part Clio and PracticePanther price out of a solo budget.

  2. 02

    Document / e‑sign

    Read returns, contracts, KYC packets. Extract fields, flag anomalies, draft engagement letters for review.

  3. 03

    Client onboarding

    Engagement letters, intake checklists, and welcome packets — drafted in‑product, not hand‑assembled at 11pm.

  4. 04

    Compliance runbooks

    Jurisdiction‑aware checklists for KYC, AML, IRS filings, and state‑bar requirements — surfaced before they become a fire.

  5. 05

    Invoicing

    Flat‑fee invoices, payment collection, and a one‑page client report — no more email‑plus‑spreadsheet cadence.

Bundled modules

What you stop stitching together.

Five bundled modules, one flat fee, one operator doing the work. Each ships its own surface; together they replace the patchwork every solo firm runs today.

Client portal
A branded, secure portal your clients can use without a manual — upload, e‑sign, message, pay in one tab.
Document intelligence
Drop in a 6‑month P&L, a stack of W‑2s, or a contract. The numbers come back extracted, variance‑flagged, and tied to the line item.
Compliance
KYC, AML, IRS, and state‑bar checklists that walk themselves — and remember the jurisdiction for next year.
Invoicing
Flat‑fee billing, payment links, and an audit trail your accountant can actually defend at year‑end.
Reporting
A one‑page client report that replaces the email‑plus‑spreadsheet cadence — generated, not assembled.
Get in early

Built for the firm of one. Priced for the firm of one.

We're onboarding a small first cohort of solo U.S. tax and bookkeeping operators. Drop your email and we'll be in touch when an early‑access seat opens up.

Join the Plumbmark waitlist
One email. We'll only email about early access — no marketing spam, no newsletter bait.

No spam — we'll only email about early access.

Rather talk to a human? Write plumbmark-u07h6r@polsia.app.

In‑page links

See the three flat‑fee tiers, or read how Plumbmark handles document collection for solo tax preparers.

Privacy & data handling

Plumbmark stores uploaded returns, contracts, and engagement packets in the U.S., segregated per firm. Document intelligence calls do not train third‑party models on your client's records. A SOC‑2 path is on the roadmap.