OpenChainGraph Suite · ART-753

Home Office & Augusta Rule

The home-office deduction under both methods, the IRC §280A(g) Augusta-rule rental exclusion, and the combined tax benefit. Three premises diverge from official sources and every divergence is shown in the result rather than hidden.

Statutory Branches FlaggedNamed RefusalsZero PIIClient-side onlyOpen Question Disclosed
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Port provenance & known divergences
Ported from ApexLogics #139 "Home Office & Augusta Rule Calculator" (al_id AL-146), fetched 2026-10-06 at https://apexlogics.org/tools/139-home-office-augusta/, HTTP 200, 39,556 bytes. Three of that page's premises differ from what the authority says, and this node corrects all three rather than reproducing them:
· Gross-income cap (DIFFERS-01). IRS Topic 509: "Regardless of the method used to compute the deduction, you may not deduct business expenses in excess of the gross income limitation." Rev. Proc. 2013-13 §4.08(2) states the same limit for the safe-harbor method. Apex #139 caps only the regular method (line 366), so it can publish a $1,500 simplified deduction against $500 of income.
· Safe harbour for a reimbursed employee (DIFFERS-04). Rev. Proc. 2013-13 §4.02: the safe harbour "does not apply to an employee with a home office if the employee receives advances, allowances, or reimbursements for expenses related to the qualified business use of the employee's home under a reimbursement or other expense allowance arrangement (as defined in §1.62-2) with his or her employer." For an S-corp owner-employee on an accountable plan, only the regular method competes here. Apex #139 reads entityTypeHO (line 363) but never uses it in the computation, and its own option label says "accountable plan reimbursement" while both methods stay in the race.
· The "10% rule" (DIFFERS-02). The source page's embedded citation calls §280A(g) the "14-day / 10% rule". The fetched text of §280A(g) contains no 10% test; its two conditions are residence status and "actually rented for less than 15 days". The 10% limb belongs to the separate §280A(d)(1)(B) residence test for mixed-use dwellings. This node drops the 10% claim.
Open legal question, contested and not settled. §280A(g)(1) reads "no deduction otherwise allowable under this chapter because of the rental use of such dwelling unit shall be allowed", which on its face bars the S-corp rent deduction that Apex #139 books and this node retains. This tool does not decide the question. It keeps the source figure, flags every qualifying S-corp run with ART753_CORP_DEDUCTION_BARRED_TEXT_280A_G_1, and leaves the answer to a tax adviser.
Home office, Augusta rule and rates
Edit any field and run. Rates are ordinary-income marginal rates you supply; the node holds no rate table and reads no clock.
Office square feet.
Total home square feet. A blank or zero here reads as 1 sq ft.
Blank auto-derives from the square feet. Typing 0 overrides to a 0% business use.
Rent, or mortgage interest if you own.
Keep depreciation out of this bucket if the simplified method may win - the safe harbour allows none.
Caps the deduction under §280A(c)(5).
§280A(g) needs ≤ 14. The statute tests days actually rented.
Comparable venue rate. Document with comps - good practice, and a claim this node does not model.
Typing 0 silently becomes 37%. 37% is a 2026 individual rate.
Typing 0 silently becomes 32%.
Result
Home office
Augusta rule · IRC §280A(g)
Combined
Compliance flags
Statutory notes & unverified premises
Fallbacks applied
Proof status
This node ships compute_proof_ready: deferred. No formal correctness proof has been produced for this kernel; the result above is a deterministic recompute, checked by boundary fixtures, not a proven one.
Execution Hash & §4 Artifact
SHA-256 execution hash (JCS canonical, RFC 8785), bare lowercase hex: