Is Your Internet Bill Tax Deductible? The Business-Use Rule, Explained

Almost every self-employed person who works from home hits this question, usually while looking at a bill that is obviously part work and obviously part streaming. The good news is that the rule is simpler than the folklore around it. The bad news is that the folklore is everywhere, and a lot of it points at an IRS publication that no longer exists.

The Rule: Business-Use Percentage, Not All-or-Nothing

Internet service is not on a list of "deductible" or "non-deductible" expenses, because it is not that kind of expense. It is a cost that serves two purposes at once, and the tax treatment follows the split. IRS Publication 587, Business Use of Your Home, puts the general principle plainly for utilities and services: they are primarily personal expenses, but if you use part of your home for business, you can deduct the business part of them.

So the question is never "can I deduct my internet?" It is "what is my business share, and can I show my working?" That reframe matters, because it changes what you need to be able to produce if anyone asks. You are not defending the existence of the deduction. You are defending a number.

In practice, "reasonable and consistent" means three things:

• Pick a method that relates to how the connection is actually used. A method you chose because it produced a bigger number is not a method.
• Write down how you derived it — the inputs, not just the answer. "45% based on 27 business hours out of 60 total online hours, sampled over October" is a record. "45%" on its own is an assertion.
• Apply it the same way every month, and across years. A percentage that moves around without a reason invites the question of why. If your usage genuinely changes — you take on a client that doubles your hours — recalculate and note when and why it changed.

Three Defensible Ways to Calculate Your Percentage

There is no IRS-blessed formula for internet specifically, which means the method is yours to choose and yours to justify. These three are the ones that hold up, each with its own weakness.

1. Time-based: business hours online ÷ total hours online

The most common and generally the easiest to defend, because it maps directly to use.

Worked example. Your internet costs $75 a month, so $900 for the year. Over a representative month you log your working hours online at 30 hours a week, and estimate total household online time — yours plus everyone else's — at 75 hours a week.

• Business-use percentage = 30 ÷ 75 = 40%
• Deduction = $900 × 40% = $360 for the year

How to document it: keep the log for the sample period, the arithmetic, and the twelve invoices. Its weakness: "hours online" is fuzzy on an always-on connection, and estimating other people's usage is genuinely hard. Sample honestly over a normal period, not your busiest week.

2. Device- or user-based: your work devices ÷ total household devices

Useful when time is hard to pin down but the household composition is obvious — for example, one freelancer and three other people who all use the connection heavily.

How to document it: a dated note listing the people and devices on the connection and which are yours for work. Its weakness: it treats every device as equal, which is rarely true. One person streaming 4K video all evening consumes vastly more of the connection than your email and video calls, and a device count will not show that. If your household skews that way, this method flatters you and is harder to defend.

3. Space-based: fold it into the home office calculation

Rather than giving internet its own percentage, you can treat it as a utility inside the actual-expense home office calculation, where it takes the same percentage as the rest of your home costs — Publication 587 notes that the business percentage for utilities is generally the same as the percentage of your home used for business.

How to document it: the square-footage measurements you already need for the home office deduction. Our home office deduction calculator runs that percentage for you. Its weakness: square footage is a poor proxy for internet usage. If your office is 8% of your home but you are online for work most of the day, this method will understate the deduction substantially. It also ties your internet number to a deduction with its own strict eligibility tests.

When You CAN Claim 100%

There is a genuine full-deduction case, and it is narrower than most people hope: a separate connection used exclusively for the business.

Publication 587 draws this line explicitly for telephone service. The basic local charge for the first telephone line into your home is a nondeductible personal expense — but the cost of a second line into your home used exclusively for business is a deductible business expense. The same logic is what supports a full deduction on a dedicated business connection: a second line installed for the business, or the connection at separate business premises.

What does not get you there:

• "I work from home full time." A full-time schedule does not make your evening and weekend personal use of the same connection disappear. This is the single most common reason a claimed 100% falls over.
• "I live alone." Living alone removes other people from the calculation, not your own personal use of the connection.
• "I upgraded the plan for work." A defensible argument for deducting the incremental cost of the upgrade, perhaps. Not an argument for the whole bill.

One important caveat on the exclusive-use route: exclusive means exclusive. A "business" line that the household also uses when the main connection is slow is a mixed-use line with extra steps.

Internet vs Home Office vs Phone: Three Separate Calculations

These three get blurred together constantly, and blurring them is how people end up either double-counting or missing a deduction entirely. They are separate:

The interaction worth knowing: if you use the simplified home office method — a flat rate per square foot — utilities are already baked into that flat amount, so there is no separate internet figure to add on top of it. If you use the actual-expensemethod, you choose whether internet sits inside that calculation as a utility or outside it as its own business expense. Either is fine. Both is double-counting.

The home office deduction has its own eligibility tests that internet does not — the space must be used regularly and exclusively for business, which trips up a lot of kitchen-table setups. That is a separate question with a separate answer; see our home office deduction calculator for the arithmetic, and our Schedule C expense guide for where each of these lands on the form.

How to Actually Track It Every Month

Here is the part that actually costs people money, and it is not the percentage. A percentage is a decision you make once. The failure mode is mundane: the bill arrives by email every month, gets glanced at, and never gets recorded. At tax time there is no total — so either the deduction gets skipped, or it gets reconstructed from memory, which is the weakest possible record.

On the example above, skipping it entirely costs you the full $360 of deduction. Not a disaster on its own. Repeated across internet, phone, software and every other recurring bill that arrives quietly by email, it adds up to a real number.

The fix is to make capture automatic rather than disciplined. Your provider emails the invoice every month; that email is the record you need. ExpenseBot reads receipts and invoices out of Gmail and writes them into a Google Sheet that stays in your own Google Drive, so twelve monthly internet invoices become a running total you did not have to think about.

It also handles the percentage itself. ExpenseBot lets you set a business use percentage per expense category — internet is the standard example — in your expense category settings. Set it once and it is applied automatically to every expense in that category, and your year-end tax report shows both the full amount you paid and the calculated business portion. That is exactly the pair of numbers this deduction needs: what the connection cost, and what share of it you are claiming.

What to Keep

A short documentation checklist. If you have these three things, the deduction is supportable:

• The bills. All twelve monthly invoices from the provider — not just the bank lines. A bank statement shows that money left your account; the invoice shows what it bought.
• The method. A written note of how you arrived at the percentage: which method, what the inputs were, and when you worked it out. One paragraph is enough. Its value is that it exists and is dated.
• The months. Any log or sample period behind the calculation, plus a note if the percentage changed mid-year and why.

Keep them for as long as you keep the rest of your records for that tax year. The percentage that is easy to defend two years later is the one that was written down at the time.

Frequently Asked Questions