An accountable plan is a written agreement between your S-corp and you as its employee. Under it, the business pays you back for business costs you covered personally: the home office, mileage, your phone, supplies, travel. Set up correctly, the payment is deductible to the corporation and is not wages to you, so it carries no income tax and no payroll tax.
Two things have to be true for that to work. The expense has to qualify. The paperwork has to exist before the money moves. This article covers both, with the arithmetic, so you can tell in about ten minutes whether the plan you have is doing its job.
What an S-corp accountable plan does, and why it matters more now
Before 2018, an S-corp owner who paid a business cost personally could still claim it on Schedule A as an unreimbursed employee expense, above a 2% floor. The Tax Cuts and Jobs Act suspended that deduction. The One Big Beautiful Bill Act, signed on 4 July 2025, made the suspension permanent, with a narrow carve-out for educator expenses.
So under current law, a business cost you pay personally and never run through the corporation produces no deduction anywhere. Not on the 1120-S. Not on Schedule A. Not on your New Jersey return.
One route remains open. The corporation reimburses you, and the corporation deducts the payment. An accountable plan is what keeps that payment out of your wages.
Treasury Regulation 1.62-2 sets three conditions. The IRS explains all three in Publication 463:
- Business connection. The cost has to be one the corporation could deduct, and one you incurred while working for the company.
- Substantiation. You record the amount, date, place, and business purpose, and you give that record to the corporation on time. The IRS does not require documentary evidence for costs under $75, except lodging, which always needs a receipt. You still keep the written record.
- Return of excess. If the corporation advances you more than you spend, you return the difference within a reasonable period.
Miss one of the three and the arrangement becomes a non-accountable plan. Every payment under it then counts as wages, which adds payroll tax on top of income tax to money that was meant to be a deduction.
First question: does the home office qualify?
This is the gate everything else passes through, and it is easy to walk past. An accountable plan can only reimburse a cost that is deductible in the first place. For a home office, that means Section 280A. Because you are an employee of your own corporation, the test is stricter than the one a sole proprietor faces. The IRS sets out the general rules in Publication 587.
The space needs to clear all four:
- Exclusive use. The area is used only for business. A dedicated room qualifies. A guest room with a desk in it does not, and neither does a dining table you clear at six o’clock.
- Regular use. This is where you normally work, not somewhere you occasionally open a laptop.
- A qualifying purpose. It is your principal place of business, which includes a space you use regularly for administrative and management work when no other fixed location serves that purpose. A place where you regularly meet clients also qualifies, as does a separate structure.
- Convenience of the employer. The corporation needs the space. Working from home because it suits you is not the same as working from home because the company provides no other office.
That fourth condition is the one worth thinking about carefully. If your S-corp also leases commercial space and you work from home some days by preference, the home office reimbursement rests on weak ground. We document the employer-convenience point deliberately: a line in the corporate resolution stating that the company provides no other work location, plus a floor plan with the square footage marked and photographs of the room. That turns a two-minute answer into the whole of the conversation if anyone ever asks.
If the space does not qualify, the plan still works for everything else. Mileage, phone, supplies, and travel remain reimbursable. The home office does not.
What the plan can reimburse
Anything the corporation could deduct if it had paid the bill directly. For a service business, that usually means four categories.
Home office costs. The business-use share of mortgage interest, property taxes, homeowners insurance, utilities, HOA fees, repairs, and depreciation.
Vehicle use. Either the standard mileage rate or a share of actual vehicle costs, supported by a mileage log. The rate needs care in 2026, because it changed mid-year. The IRS set the business rate at 72.5 cents per mile in December 2025, then raised it to 76 cents effective 1 July 2026. Miles driven from January through June use 72.5 cents. Miles driven from July through December use 76 cents. Reimbursing the whole year at one rate either shortchanges the second half or overpays the first, and an overpayment brings the return-of-excess rule into play.
Cell phone and home internet. The business-use share. Cell phones stopped being listed property in 2010, so call-by-call records are not required. A documented, reasonable allocation is enough, and the same reasoning applies to internet.
Supplies, subscriptions, dues, and travel paid on a personal card, including the client dinner you charged to the wrong card.
The plan does not have to cover every category, and it does not have to treat every employee alike. You can write it to reimburse the owner-employee for home office and mileage only. Accountable plans carry no nondiscrimination rule of the kind that applies to retirement plans.
How to calculate the home office reimbursement
The IRS offers a simplified home office method: $5 per square foot, capped at 300 square feet, so $1,500 at most. That safe harbor is closed to you here. Section 4.02 of Revenue Procedure 2013-13 states that the simplified method does not apply to an employee who receives reimbursements under an arrangement covered by Treasury Regulation 1.62-2. Running reimbursements through your S-corp puts you on the actual expense method.
Four steps:
- Measure the square footage used exclusively and regularly for business. Divide by the total square footage of the home. That is your business-use percentage.
- Apply the percentage to your actual annual costs: mortgage interest, property taxes, homeowners insurance, utilities, HOA fees, repairs and maintenance.
- Add the same share of depreciation on the structure. Take the purchase price less land, depreciate it straight-line over 39 years, and multiply by your percentage.
- Total the result. That is what the corporation reimburses and deducts.
Two points inside that calculation move real money, in opposite directions.
Mortgage interest and property taxes get deducted once, not twice. When the corporation reimburses the business-use share of those two items, that same share comes off your Schedule A. We see this missed often enough that it is worth stating plainly, and it is visible on a return.
Depreciation is worth claiming, and the usual argument for claiming it is overstated. The familiar line is that the depreciation gets taxed on sale whether or not you ever deducted it, so you may as well take it. The rule is narrower than that. Section 1250(b)(3) provides that if you can establish by adequate records that the amount actually allowed was less than the amount allowable, the smaller allowed amount is what counts. The IRS confirms the same point in its guidance on depreciation and the sale of a home used for business. So skipping depreciation does not automatically create phantom tax later. It does throw away a deduction every year, which is reason enough to claim it.
Here is the real trade. Under Section 121(d)(6), gain on the sale of your home attributable to depreciation taken after 6 May 1997 falls outside the $250,000 or $500,000 primary-residence exclusion. That gain is generally unrecaptured Section 1250 gain, taxed at a federal maximum of 25%. You are exchanging a deduction now at your ordinary rate for a capped rate later, with the timing in your favour. For most owners the exchange is worth making. If you expect to sell within two or three years and the gain sits well inside the exclusion, run the numbers before deciding.
One more question is where these deductions do the most good. Mortgage interest and property taxes can be deducted personally, but the personal deduction has ceilings the corporate one does not. The federal SALT cap stands at $40,400 for 2026 and phases down above roughly $500,000 of modified AGI. New Jersey caps its property tax deduction at the lesser of taxes paid or $15,000, and allows no mortgage interest deduction at all. A corporate reimbursement meets none of those limits and works whether or not you itemise. For a New Jersey owner already above the SALT cap, moving the business-use share into the corporation turns a deduction that was producing nothing into one that produces full value.
What this looks like in dollars
The figures below describe one set of assumptions. Your own numbers will differ, and the assumptions are stated so you can substitute your own.
Take a solo professional practice in New Jersey. No outside office. One dedicated room of 240 square feet in a 2,400 square foot home, so a business-use percentage of 10%.
Annual household costs: mortgage interest $18,000, property taxes $12,000, homeowners insurance $2,200, utilities $4,800, repairs and maintenance $1,800. Building basis, after taking out land, is $455,000, so straight-line depreciation runs $11,667 a year.
The 10% shares come to $1,800 of mortgage interest, $1,200 of property tax, $220 of insurance, $480 of utilities, $180 of repairs, and $1,167 of depreciation. Home office total: $5,047.
Add what she was already paying personally. Business mileage of 3,800 miles, split evenly across the rate change, gives $1,377.50 for the first half and $1,444 for the second, so $2,821.50. Cell phone at 65% business use of a $1,740 annual bill: $1,131. Home internet at 40% of $1,020: $408.
The corporation reimburses her $9,407.50, tax-free, and deducts the same amount.
That total is two different things, and they are not worth the same.
New deductions: $6,407.50. Insurance, utilities, repairs, depreciation, mileage, phone, internet. Before the plan, none of these dollars was deductible on any return. Assuming a 32% federal marginal rate, reduced to an effective 25.6% by the Section 199A qualified business income deduction, plus New Jersey’s 6.37%, the plan saves her roughly $2,050 in the first year — repeating annually, on spending she was doing anyway.
Relocated deductions: $3,000. The mortgage interest and property tax share. These come off Schedule A, so the gain is the difference between what they were worth there and what they are worth inside the corporation. If she was already above the SALT cap, the $1,200 property tax share was producing no federal benefit and now produces full benefit. That part is real, and it depends on her return, so we model it rather than estimate it.
Notice which items carry the weight. Utilities, insurance, repairs, depreciation, mileage, and phone. Mortgage interest, the number most owners reach for first, contributes the least.
When the paperwork has to happen
Treasury Regulation 1.62-2(g)(2) offers two safe harbors. Either one removes the argument about what “reasonable” means.
The fixed-date method. Three timings, applied to each expense. An advance is timely if the corporation pays it within 30 days before you incur the cost. Substantiation is timely if it reaches the corporation within 60 days after. An excess advance is timely returned within 120 days after. Most owner-employees reimburse after the fact rather than in advance, and for them only the 60 days matters.
The periodic statement method. The corporation issues statements at least quarterly showing amounts paid but not yet substantiated, and asks the employee to substantiate or return them. Anything handled within 120 days of the statement counts as timely. This suits businesses running standing advances. Most solo S-corps have no use for it.
You can work outside these windows. Doing so turns “reasonable” into a facts-and-circumstances question rather than an automatic pass, which is a conversation better had in advance than during an examination. A monthly or quarterly cycle handles it: submit, reimburse, file. Reconstructing a year of mileage and utility bills in December reads as assembled after the fact, because it was.
What it costs when the plan does not hold
Here is what happens, in order.
The IRS treats the arrangement as a non-accountable plan. The reimbursements move into your W-2 wages. You owe income tax on them. Payroll tax applies on top, and the amount depends on where your salary already sits. Below the 2026 Social Security wage base of $184,500, the cost is 7.65% from you and 7.65% from the corporation. Above it, the Social Security portion is already maxed out, so the additional cost is 1.45% Medicare on each side, plus the 0.9% surtax on your side above $200,000 of wages, or $250,000 filing jointly.
The corporation still deducts the wages, so this is not a total loss. But a tax-free reimbursement has become taxed compensation carrying payroll tax, which is the opposite of the intended result.
The regulations do not literally require a written plan. Put it in writing anyway. A dated board resolution or written policy, kept with the corporate records, costs nothing and answers the first question an examiner asks.
How New Jersey treats these reimbursements
New Jersey follows the same logic, and the state rules make a compliant plan more valuable here rather than less.
Under the New Jersey Gross Income Tax Act, all earnings connected with employment are reported as wages, and an employee cannot deduct employment-related costs from gross income. The state never adopted the federal deduction for unreimbursed employee expenses, before or after the TCJA. A business cost you absorb personally in New Jersey has never produced a state deduction.
What the state does allow is excluding a properly handled reimbursement from wages. The Division of Taxation applies a three-part test that tracks the federal standard: the expenses are job-related, the taxpayer is required to and does account for them to the employer, and the reimbursement equals the exact amount of the allowable expenses. Meet all three and the payment stays off your New Jersey wages. The Division has addressed the third condition directly in the travel context: a reimbursement paid with a gross-up no longer matches the substantiated amount, so the whole payment becomes taxable salary.
Two New Jersey specifics to coordinate with your preparer. First, the business-use share of property taxes reimbursed by the corporation comes out of the property taxes you claim under New Jersey’s separate deduction, which is capped at the lesser of taxes paid or $15,000. Second, New Jersey allows no mortgage interest deduction, which means the business-use share of your mortgage interest is worth more inside the corporation than outside it at the state level.
Who this does not apply to
An accountable plan is an arrangement between an employer and an employee. If you are not an employee of a corporation, a different mechanism applies to you.
Sole proprietors and single-member LLCs deduct the home office directly on Form 8829 and Schedule C, and may use the $5-per-square-foot simplified method. There is no employer to reimburse them.
Partners in a partnership or multi-member LLC generally deduct unreimbursed partnership expenses on Schedule E, where the partnership agreement requires the partner to bear them.
Renters can use an accountable plan in full. The business-use share of rent, renters insurance, and utilities is reimbursable. Only the depreciation component drops out.
Owners with a company-provided office elsewhere should get advice before claiming the home office share, because the convenience-of-the-employer condition is the one that most often fails.
Setting it up
- Confirm the space qualifies against all four Section 280A conditions, before calculating anything.
- Adopt the plan in writing. A corporate resolution stating that the corporation reimburses employees for substantiated ordinary and necessary business expenses, naming the categories covered and the substantiation and return-of-excess requirements. Date it, sign it, file it.
- Document the space. Floor plan with square footage, photographs, and a statement of why the corporation provides no other work location.
- Build the expense report once. Date, amount, place, business purpose, category. The home office gets its own annual worksheet showing the percentage and each cost line.
- Reimburse on a fixed cycle, monthly or quarterly, inside the 60-day window. Pay from the business account to your personal account, described as an expense reimbursement rather than a distribution or a payroll item.
- Keep it off the W-2. A correctly handled reimbursement is not wages and does not appear in Box 1.
- Reconcile at year end. Check that reimbursed mortgage interest and property taxes came off Schedule A, that the home office depreciation schedule is being tracked for eventual sale, and that mileage used the correct rate for each half of 2026.
What to do next
Here is where this lands. If you own an S-corp in New Jersey and cover home office, mileage, phone, or other business costs personally, those dollars currently produce no deduction on any return. With a plan in place, substantiated on a regular cycle and paid at the exact amount documented, the same dollars become a deduction for the corporation and tax-free cash for you. Nothing about your spending changes. Only the paperwork does.
Five things determine whether it holds: the qualification test, the calculation method, the Schedule A adjustment, the substantiation cycle, and the corporate resolution. We build all five together, sized to what you actually spend rather than to a template, and we document the position in a form that answers questions rather than raising them.
If you already have a plan, a twenty-minute review will tell you which of the five are in place. If you do not have one yet, the setup runs a single meeting, and the deduction starts with the next reimbursement cycle.
