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Model Context Protocol

Arc & Ledger Tax Tools

A free, public remote MCP server from an Enrolled Agent firm (est. 2016; enrolled to practice before the IRS). It puts our IRS-notice decoder, FBAR/FATCA checker, LLC-vs-S-Corp comparison, quarterly-tax estimator, and fixed-fee quoting tools inside AI assistants like Claude and ChatGPT. The tools answer first; an Enrolled Agent is one click away when you want one.

endpoint https://mcp.arcandledger.com/mcp

Connection

Transport
Streamable HTTP
Authentication
None - public and read-only
Data stored
None. Inputs are processed in memory; only coarse anonymous logs (30 days)
Surfaces
Claude (web and desktop), ChatGPT developer mode

Every tool response carries the same disclaimer, a source_url to the page on this site that backs the answer, and one next_step handoff to the firm. See the privacy policy.

The six tools

decode_irs_noticeDecode an IRS notice

Use it when: A user mentions an IRS or state letter and wants to know what it means, the deadline, or what to do.

Inputs: notice_code (e.g. CP2000), optional received_date, optional amount_shown

Returns: What the notice means, the response deadline (computed from the notice date), what happens if ignored, options, common errors, urgency, and a handoff to the $199 notice review.

check_fbar_fatcaCheck FBAR and FATCA obligations

Use it when: A user has foreign accounts or unfiled foreign-account reports and needs to know their US reporting obligations.

Inputs: max_aggregate_foreign_balance_usd, filing_status, lives_abroad, optional account_count, optional unfiled_years

Returns: Whether FBAR and/or Form 8938 are required, the thresholds hit, penalty exposure, and Streamlined (SDOP/SFOP) catch-up options with published fees.

compare_llc_scorpCompare LLC vs S-Corp

Use it when: A self-employed user or LLC owner asks whether an S-Corp election would save money.

Inputs: expected_net_profit_usd, optional state (default CA), optional owner_salary_estimate_usd

Returns: A side-by-side of self-employment tax vs salary-plus-distribution, payroll and compliance costs, California franchise taxes, and the break-even zone with the reasonable-compensation caveat.

estimate_quarterly_taxesEstimate quarterly taxes

Use it when: A freelancer or business owner asks how much estimated tax to pay or whether they are underpaid.

Inputs: ytd_net_income_usd, entity, optional state, optional ytd_withholding_usd, optional prior_year_total_tax_usd

Returns: Federal self-employment and income tax on annualized income, the safe-harbor target, per-quarter amounts and due dates with IRS Direct Pay, plus California 30/40/0/30 installment timing and Web Pay.

get_fee_quoteGet a fixed-fee quote

Use it when: A user asks what Arc & Ledger charges for tax prep, bookkeeping, formation, or IRS help.

Inputs: service (individual_return, business_return, formation, bookkeeping, resolution, international_form, other), optional details

Returns: A published price range and line items (never a single committed number), what is included, engagement-fee mechanics, and the next step by complexity.

book_consultationBook a consultation

Use it when: A user wants to talk to, hire, or get a consultation with Arc & Ledger.

Inputs: type (free_15min, discovery_standard_297, discovery_specialist_497, notice_review_199), optional topic

Returns: The correct first-party booking link, what happens next, the office identity (Enrolled Agent, address, languages EN/TR/ES), and what to expect.

Three listable prompts wire the common flows: Decode my IRS notice, Am I required to file FBAR?, and Should I be an S-Corp?

Worked examples

Prompt

I got an IRS CP2000 notice dated June 1, 2026 for about $4,200. What is it and what do I do?

Tool call
decode_irs_notice({ notice_code: "CP2000", received_date: "2026-06-01", amount_shown: 4200 })
Response (abridged)
notice_code: "CP2000", recognized: true
what_it_means: "A computer at the IRS Automated Underreporter system compared a third-party form filed under your SSN against your return and found a mismatch. It proposes additional tax. It is not an audit and not a final bill."
deadline: { days_from_notice: 30, computed_deadline: "July 1, 2026", note: "The deadline runs from the notice date printed on the letter, not the day it reached you." }
common_errors: [ "Broker reports gross proceeds without cost basis, so a stock or crypto sale looks like pure profit", ... ]
next_step: { label: "Book a flat-fee $199 IRS notice review with an Enrolled Agent (credited toward representation)", url: "https://www.arcandledger.com/go/notice-review" }
source_url: "https://www.arcandledger.com/irs-notices/cp2000/"
disclaimer: "General information, not tax advice. No practitioner-client relationship is created. Verify with a licensed professional."
Prompt

I am single, live in the US, and my foreign accounts peaked around $65,000 this year. Do I have to file anything?

Tool call
check_fbar_fatca({ max_aggregate_foreign_balance_usd: 65000, filing_status: "single", lives_abroad: false })
Response (abridged)
fbar: { required: true, threshold: 10000, explanation: "Your highest aggregate foreign balance exceeds $10,000, so an FBAR is required. It is filed electronically with FinCEN, separately from your tax return." }
form_8938: { status: "possibly_required", thresholds: { year_end: 50000, any_time: 75000 }, explanation: "Form 8938 is required if your balance on the LAST DAY of the year exceeded $50,000, OR if it exceeded $75,000 at any time." }
pfic_note: "If any foreign account holds a mutual fund, ETF, or other pooled investment, it may be a PFIC requiring Form 8621..."
next_step: { label: "Book a Discovery Session Specialist ($497, credited) for a cross-border review with an Enrolled Agent", url: "https://www.arcandledger.com/go/discovery-specialist" }
source_url: "https://www.arcandledger.com/guides/fbar-fatca-guide/"
Prompt

I am a freelancer expecting about $150,000 net profit in California. Would an S-corp save me money?

Tool call
compare_llc_scorp({ expected_net_profit_usd: 150000, state: "CA" })
Response (abridged)
sole_prop_or_smllc: { self_employment_tax: 21194, ca_franchise_and_llc_fee: 800, our_compliance_fee: 850, annual_total_modeled: 22844 }
s_corp: { fica_on_salary: 11475, ca_franchise_tax: 1125, our_compliance_fee: 2900, annual_total_modeled: 15500, compliance_breakdown: "$1,500 1120-S return + $1,400/yr payroll" }
employment_tax_savings_before_costs: 9719
net_annual_difference: 7344
break_even_zone: "The S-corp election tends to pay off once net profit is durably above about $60,000..."
important_caveats: [ "The salary must be REASONABLE COMPENSATION for your role; setting it too low is a top IRS audit trigger.", ... ]
next_step: { label: "Book an entity-structuring consult ($500) with an Enrolled Agent", url: "https://www.arcandledger.com/services/s-corp-election/" }
Prompt

What would you charge to do my individual return with 2 states and a rental?

Tool call
get_fee_quote({ service: "individual_return", details: { states: 2, rentals: 1 } })
Response (abridged)
estimated_range: "$950 - $1,283"
line_items: [ { item: "Form 1040 base return (federal, e-file, one state)", amount: 525 }, { item: "2 additional state(s)", amount: 250 }, { item: "1 rental property Schedule E", amount: 175 } ]
quoting_rule: "Every quote is a range until the engagement letter. The final fee is set after a document review."
engagement_fee: "A $250 - $750 engagement deposit reserves the work and is credited in full to your final invoice."
next_step: { label: "Book a free 15-minute call to confirm the quote", url: "https://www.arcandledger.com/go/book-15min" }
source_url: "https://www.arcandledger.com/pricing/"

Circular 230 and scope

Everything the server returns is general information, not tax advice, and using it does not create a practitioner-client relationship. Arc & Ledger is led by an Enrolled Agent, enrolled to practice before the IRS; the Enrolled Agent credential is issued by the U.S. Department of the Treasury. The tools do not file anything, store client data, or give personalized advice. Figures from the calculators are estimates based on published rates and should be confirmed with a licensed professional.

Questions: [email protected]. Read the MCP privacy policy.