Title agency calculator

Title Agency & Closing Cost Calculator

Computes a closing instead of reading one. Give it a price and it derives every statutory charge, applies a recorded agency rate card, prorates the taxes, and reports the seller's net and every cost ratio.

When to use

• Quoting what a sale will cost before a statement exists.
• Checking a statement someone sent you against what the numbers should be.
• Choosing between title agencies on price.
• Sizing or capping a seller concession.
• Answering "what percentage of the sale price is that".

Not for: QA of a received settlement statement → title-closing-review. Loan documents, Note/Mortgage/Guaranty → real-estate-closing-check.

The engine

scripts/closing_calc.py. Run the self-test first, every time.

python3 scripts/closing_calc.py selftest    # must print ALL PASS
python3 scripts/closing_calc.py cards       # show every recorded rate card

The self-test reproduces three real closings to the penny — 8 Pine Track under both agencies and the closed 31 Juniper file. If it does not print ALL PASS, a rate card or a statutory rate has drifted. Fix that before quoting anything.

# full estimate
python3 scripts/closing_calc.py estimate \
    --price 279000 --agency marion-lake --loan 270630 --deposit 3000 \
    --close 2026-08-24 --annual-tax 290.11 --commission 4.5 \
    --basis 210474.47 --sf 1400 --notary 175

# concession as a share of the buyer's costs, with a cap
python3 scripts/closing_calc.py estimate --price 279000 --agency marion-lake \
    --loan 270630 --close 2026-08-24 --annual-tax 290.11 \
    --concession-pct 50 --concession-cap 3500

# side-by-side agency comparison, notary forced onto both cards
python3 scripts/closing_calc.py compare --price 279000 --loan 270630 \
    --close 2026-08-24 --annual-tax 290.11 --commission 4.5

Useful flags: --strike-junk (drop technology / warehousing / ID-verification / escrow- disbursement fees), --exact-premium (price the owner's policy on the exact sale price rather than rounding coverage up), --survey, --noc-pages, --mortgage-pages.

The four rules this skill exists to enforce

1 — Quote the cost ex-commission and ex-concession. A commission is a brokerage cost and a concession is a price adjustment; neither is a cost of closing. Folding them in inflates the percentage and hides the real number. Report closing costs ex-commission as the headline, then show commission and concession separately.

2 — Only the title-agency bucket is shoppable. Deed stamps, the owner's premium and recording are fixed by Florida law or promulgated rate — identical at every agency in the state. On a typical file ~75% of non-commission closing cost cannot be negotiated by anyone. Comparing agencies on anything but their own fees compares noise.

3 — Normalise before comparing. Agencies leave different things off. One quote omits the notary, another omits the proration; whichever is missing makes that agency look cheaper. Force the same line items onto both cards (--notary) before drawing a conclusion. This flips the answer more often than not.

4 — Distinguish what the agency keeps from what it collects. A fee payable to the agency is its revenue. A fee payable to a search vendor, underwriter or Simplifile is a pass-through you pay anywhere. keeps vs passed through in the output.

Reading the output

Figure	What it means
CLOSING COSTS — EX-COMMISSION, EX-CONCESSION	The headline. Benchmark 1.0%–3.0% of price in FL
TITLE AGENCY TOTAL	The only shoppable bucket. Typically 0.25%–0.40% of price
the agency keeps	The agency's actual revenue — what a discount request targets
ALL-IN TITLE	Agency fees + promulgated premium
% of gross margin	On a build-to-sell, the number that matters. Closing costs routinely eat 25%+ of margin

The tool prints % price, % basis, % margin and per-square-foot. On a spec build the margin ratio is the honest one: 1.6% of price is 6.7% of margin.

Traps this tool is built around

• Prepaids and escrow reserves are not modelled. A financed buyer usually adds $3,000– $6,000 in prepaid interest, hazard premium and tax/insurance reserves. If a draft HUD shows blank 900 and 1000 series, it is incomplete. Never agree to a percentage concession before seeing the buyer's Loan Estimate — and a flat concession larger than the buyer's actual costs is forfeited, not refunded to the seller.
• New-construction proration is deceptively small. Florida assesses as of 1 January, so the construction year is taxed on land only. The following year picks up the house and the bill multiplies ~10×. Small at this closing, large for the next one.
• A missing line is not a saving. An omitted proration or notary will be added before funding. Add it yourself before comparing.
• Cap percentage concessions in the contract. "50% of buyer's closing costs, not to exceed $X" — otherwise an inflated buyer cost sheet expands the seller's exposure without limit.
• Check the transaction type before reusing a rate card. A multi-property loan closing prices nothing like a one-house sale. The loan cards are marked as such.

Adding a rate card

Add an entry to CARDS in the script: seller and buyer fee dicts, keeps listing the lines payable to the agency itself, notary_quoted, and a context string naming the source document and transaction type. Then add an assertion to selftest() against a real statement from that agency — a card without a self-test assertion is not trustworthy.

Reference

references/fl-rates-and-ratecards.md — statutory formulas and worked examples, the recorded rate cards with provenance, Florida benchmarks, the full 8 Pine Track closing-cost record, the closed 31 Juniper comparable, and the open items on the live deal.