Can I claim business expenses if I work from clients’ premises?

Understanding what counts as a “business expense” when you work on-site

If you spend most of your working week at clients’ premises—consulting at their office, delivering services at their site, or working on projects inside their facilities—it’s natural to ask whether you can still claim business expenses. You’re not working from your own office or home, so surely the costs you incur to do the job should be deductible, right?

In principle, business expenses are costs that you incur wholly and exclusively to run your business or perform your work. Working from clients’ premises doesn’t prevent you from claiming expenses. What it changes is the pattern of costs you’re likely to incur, the way you justify them, and the risk areas you need to avoid—especially around travel, subsistence, accommodation, and “dual-purpose” spending that benefits you personally as well as the business.

This article explains how to think about business expenses when your day-to-day work happens on a client’s site. It also highlights the types of costs that are commonly allowable, the categories that often cause problems, and the practical steps you can take to keep your claims defensible, consistent, and well-documented.

Why the location of your work matters

Where you work affects whether certain costs are treated as business-related or personal. For someone who works entirely from a dedicated office, travel might be occasional and clearly job-specific. For someone who works from home, some household costs can sometimes be apportioned. But if you work primarily on clients’ premises, travel and on-site costs become routine—and routine costs are precisely where tax authorities tend to scrutinize whether the expense is truly business-only or just part of “getting yourself to work.”

The main distinction is this: costs that are necessary to perform your duties or deliver your services may be deductible, while costs that are essentially personal living costs or commuting costs typically are not. Working at a client’s premises can blur the line between “travel for work” and “commuting,” especially when the same client site becomes a near-permanent place of work.

The key tests: wholly and exclusively, and business purpose

At the heart of allowable expenses is a simple idea: you can generally claim a cost when it is incurred for the business and not for personal reasons. In practice, this involves a few common-sense tests:

1) Was the expense necessary for your business activity? This doesn’t mean it must be unavoidable, but it should have a genuine business purpose tied to earning income or delivering services.

2) Was it incurred wholly and exclusively for business? If it has a personal element, you may need to apportion it (where that is permitted), or it may become disallowable altogether if it is inherently dual-purpose.

3) Can you explain the “why” and the “who”? A receipt alone isn’t always enough. You should be able to explain why the cost was incurred, and which client or project it relates to.

Working from a client site doesn’t invalidate these tests. It just means you need to apply them consistently and be cautious about habitual expenses that might look like normal living costs.

Travel: the biggest category for people who work on client premises

For many on-site workers, travel is the largest expense category. But travel is also where people make the most mistakes. The crucial question is whether your travel is a business journey or ordinary commuting.

Business travel vs commuting: the practical distinction

Commuting is generally the cost of traveling from your home (or usual base) to a permanent or regular place of work. Business travel is travel you undertake to carry out your work, such as visiting clients, traveling between sites, or going to a temporary workplace.

When you work at clients’ premises, you may think, “I’m always traveling for business.” Sometimes that’s true—especially if you have multiple clients or sites and your schedule changes frequently. But if you spend long periods at the same client site, it can start to resemble a regular workplace. In that situation, travel to that site can be treated more like commuting, depending on the circumstances.

A good habit is to ask: If this client site were my employer’s office, would my travel to it look like a daily commute? If the answer is “yes,” that’s a signal to be extra careful. The more stable and predictable the location becomes, the more it may be viewed as a permanent or regular place of work.

Claimable travel costs when the trip is business-related

When your travel is legitimately for business, common deductible costs can include:

Vehicle costs: mileage claims (if you use a mileage method), or fuel, insurance, repairs, and depreciation (if you use actual cost methods), depending on how your business accounts for vehicle use.

Public transport: train, bus, underground, tram, or taxi fares related to business travel.

Parking and tolls: costs that are directly related to business journeys.

Business-related congestion or road charges: where they relate to a business journey.

Travel between client sites: if you visit multiple locations in a day, the travel between them is typically easier to justify as business travel than a simple “home to one site” pattern.

Even for clearly business travel, the quality of your recordkeeping matters. Travel is a category where it’s easy for claims to drift over time, so logs and clear descriptions help keep things grounded.

Subsistence: meals and refreshments when you’re on-site

Subsistence—food and drink while working—can be a confusing area. People often assume that if they’re away from home for work, meals are automatically claimable. In reality, meals can easily look like normal personal consumption, which makes the rules stricter.

Generally, a meal is more likely to be claimable if it is incurred because you are traveling for work or working away from your normal base in a way that creates an additional cost you would not otherwise have had. If you buy lunch at a client site every day as a matter of routine, it can be viewed as ordinary personal expenditure. However, if you are traveling to a temporary site, or your work pattern forces you to incur extra costs, the justification can be stronger.

To keep subsistence claims sensible and defensible, aim for moderation and clarity. A modest meal during a business trip looks very different from claiming frequent expensive meals that could be interpreted as lifestyle spending.

What makes subsistence “look right” in practice

While every situation differs, the following practical factors help:

Business necessity: you were required to travel or be on-site and couldn’t reasonably eat at your usual base.

Additional cost: the meal is an extra cost arising from work travel, not simply your regular lunch that you’d buy anyway.

Reasonableness: costs are in line with what a sensible person would spend in the circumstances.

Documentation: receipts plus a note of the client/project and why you were away from your base.

Accommodation and overnight stays

If working on client premises requires you to stay overnight—perhaps the client is far away, the project requires early starts, or travel times would be impractical—accommodation can be an allowable expense when it’s necessary for the business.

However, accommodation becomes problematic when it slides into personal benefit. For example, extending a work trip into a leisure break, bringing family members, upgrading to luxury accommodation without a clear business reason, or choosing a location for personal convenience can introduce a personal element that may need to be split or disallowed.

When accommodation is genuinely for work, keep the claim straightforward: the hotel bill, necessary taxes, and reasonable incidental costs that directly relate to the business stay. If there’s a mix of business and personal time, separate the costs as cleanly as possible and keep notes explaining the split.

Equipment and tools you need on client sites

Working at client premises often means you need portable equipment: laptops, monitors, specialist tools, safety equipment, or industry-specific devices. These are typically easier to justify as business expenses because their purpose is directly tied to delivering services.

Common examples include:

Computing equipment: laptops, tablets, monitors, keyboards, mice, power banks, and protective cases.

Specialist tools: equipment required to perform the contracted work.

Software and subscriptions: project management tools, design software, security software, or professional databases.

Mobile phone costs: business calls and data usage, or an apportioned share of a plan used for both business and personal purposes.

On-site essentials: adapters, cables, portable Wi-Fi, and other items needed to function effectively at the client site.

The main pitfall is personal use. Many items—especially computers and phones—have mixed use. In those cases, you’ll want a reasonable method for apportioning costs, or a clear policy that defines what portion is business use.

Protective clothing, uniforms, and site-specific requirements

Some client sites require specific protective equipment or clothing: safety boots, high-visibility jackets, hard hats, protective eyewear, or other gear. If these items are necessary for you to access the site and perform your work safely, they often have a strong business rationale.

Where things become tricky is “regular clothing” that simply looks professional—suits, shirts, dresses, and everyday shoes. Even if a client expects a professional appearance, ordinary clothing is commonly treated as personal. Site-mandated protective equipment is a clearer case than general wardrobe costs.

Consumables, minor materials, and on-site incidentals

Depending on your profession, you might use small consumables on-site: stationery, printer paper, cables, batteries, cleaning materials for equipment, or minor parts. If these are used to deliver your service and aren’t primarily personal, they usually fit neatly into business expenses.

Be careful about “incidentals” that are really personal convenience items. For example, buying snacks, toiletries, or non-essential items while on-site can look like normal personal spending unless there is a clear business reason.

Client entertaining: proceed carefully

Working on client premises can lead to social situations—lunch meetings, coffee catch-ups, post-project dinners. Some people assume that anything involving a client is a business expense. In practice, client entertaining is a high-risk category and often subject to restrictions.

Even where some entertaining costs are permitted in your jurisdiction or accounting method, they can be limited or disallowed, and the recordkeeping expectations are higher. If you do claim any entertaining costs, document the purpose and attendees, keep receipts, and treat it as an exception rather than a routine spending pattern.

Training, certifications, and professional development

On-site work may require ongoing training: health and safety courses, compliance certifications, or professional development to maintain competence. These costs can often be business-related, especially when they maintain or enhance skills you already use in your work.

What tends to be problematic is training that represents a step into a new trade or a fundamentally new line of business. If the training is aimed at starting a different career direction rather than improving your current work, it may be treated differently. If your work at client premises depends on certain certifications, keep copies of course confirmations and evidence of how the training relates to current projects.

Insurance and professional protection

Many client contracts require you to carry certain insurances—professional indemnity, public liability, employer’s liability (if relevant), or cyber insurance. These are typically straightforward business costs because they are directly connected to your ability to trade and to meet contractual obligations.

If a client requires you to have a specific coverage level, keep a copy of the contractual clause or onboarding requirement. It helps show that the cost is a necessary part of doing business with that client.

Professional fees, memberships, and licensing

If your work depends on being registered with a professional body or holding a licence, associated fees are often claimable. Examples might include professional memberships, practising certificates, or industry accreditations that you need to access certain client sites or meet project standards.

Again, the key is connection: the membership should be relevant to your current work, not purely a personal interest group. If the membership comes with personal perks, focus on the business justification and avoid claiming optional add-ons that look personal.

Working from clients’ premises does not mean you have no “base”

It’s easy to think: “I don’t have an office, so my base is wherever the client is.” But most workers still have some form of base, even if informal—a home office area, a registered business address, or a co-working space. Your base matters because it influences travel and subsistence claims and helps distinguish business journeys from commuting-style travel.

If you do administrative work at home—planning, invoicing, reporting, client communications—that is part of your business operations, even if the core service is delivered on-site. Keeping a clear picture of where your business is managed from can help explain why certain travel is undertaken and why certain costs arise.

Home office costs: still possible, but be honest about usage

If you regularly do admin work at home—writing reports after a day on-site, managing client correspondence, preparing proposals, maintaining records—you may be able to claim some home office costs, depending on local rules and the extent of business use.

Home office claims often require a reasonable basis: either a flat-rate method (where available) or an apportionment of household costs based on time and space used for business. The risk here is overclaiming. If you spend most working hours on client premises, a very large home office claim may look inconsistent unless your home is genuinely used for significant business activity outside those hours.

Co-working spaces and rented offices

Some on-site professionals rent desk space or a small office for meetings, phone calls, or focused work. If you rent such a space primarily for business, the cost can be easier to justify than home office apportionments. It also provides a clearer “base” for the business, which may help support certain travel patterns in some circumstances.

If you use a co-working space, keep the contract and invoices, and note what you use it for: admin, meetings, secure calls, storing equipment, or other business needs.

Expenses your client reimburses

Many contracts provide for reimbursement of travel, accommodation, or other project expenses. If a client reimburses you, the accounting treatment matters. In general terms, reimbursements may count as business income, and the corresponding cost may be claimed as an expense, resulting in a net zero effect. But the exact handling depends on how you invoice and how your accounting is structured.

The practical takeaway is to keep reimbursements and expenses clearly matched. If you invoice the client for travel separately, make sure the related receipts and mileage logs tie to that invoice. If the client pays directly for your hotel or books travel for you, don’t also claim the cost as if you paid it.

Per diem and flat-rate arrangements

Sometimes a client offers a daily allowance or a fixed sum for expenses rather than reimbursing actual receipts. This can simplify your life, but it can also introduce confusion: do you still claim the actual costs, or just treat the allowance as income? The answer depends on the rules that apply to you and the arrangement you’ve agreed.

From a practical standpoint, keep a copy of the contract terms and track what the allowance is meant to cover. If you’re using an allowance, avoid also claiming the same category of costs in a way that doubles the benefit.

Common mistakes when claiming expenses while working at client sites

Here are some frequent pitfalls that catch people out:

Assuming every trip is business travel: if one client site becomes your regular workplace, travel to it can be treated like commuting.

Claiming routine lunches as subsistence: everyday meals are often personal unless there is a clear work-travel-related reason.

Mixing personal and business costs without apportioning: phones, laptops, and vehicles often have mixed use, and that needs a reasonable approach.

Overclaiming “incidentals”: small personal purchases can accumulate and create a pattern that looks like lifestyle spending.

Poor recordkeeping: a pile of receipts with no context is less defensible than fewer receipts with clear notes.

Recordkeeping: how to make your claims easier to support

If you want to claim expenses confidently, build a documentation habit that fits your workflow. You don’t need to create a bureaucratic nightmare; you just need enough clarity that someone else could understand what you did and why.

Practical steps include:

Capture receipts promptly: scan or photograph receipts as you incur them, and store them in a structured way.

Add a brief note: for travel and subsistence, note the client name, project, location, and purpose.

Maintain a mileage log: record date, start and end points, miles/kilometres, and purpose. If you use an app, ensure it produces an exportable report.

Separate business accounts: using a separate business bank account and card can reduce errors and make categorisation easier.

Be consistent: the most defensible expense claims follow a consistent pattern aligned with your work reality.

How to think about “temporary” vs “regular” client premises

People who work at client sites often rotate between projects. One month might be a short engagement in one city; another month might be a longer assignment at a single site. The longer and more predictable the assignment, the more it can look like a regular place of work.

A useful way to approach this is to classify your client-site work into two broad buckets:

Rotating/short-term sites: multiple sites, changing locations, short engagements, frequent movement between clients.

Long-term/single-site engagements: one client site for an extended period, regular attendance, predictable hours, a pattern similar to employment commuting.

When you’re in the first bucket, travel between sites and to different client locations generally has a clearer business travel profile. When you’re in the second bucket, your travel may be questioned as commuting-like, and subsistence can look like ordinary daily spending. Recognising which bucket you’re in at any given time helps you apply a consistent, defensible approach.

Examples to illustrate what is usually claimable and what is risky

Example 1: Consultant visiting multiple clients
You work with three clients each week, visiting different sites on different days, often traveling between them. Your travel costs and mileage are closely tied to client visits. In this scenario, travel is more clearly for business, and travel between client sites is especially straightforward.

Example 2: Contractor on a six-month on-site project
You work at the same client premises Monday to Friday for six months. Your travel becomes routine. Depending on applicable rules, this can start to resemble commuting. You may still have claimable expenses (such as tools, site-specific equipment, and certain travel between business meetings), but “home to site” travel is more likely to be scrutinized.

Example 3: Overnight stay for a distant client
A client requires you on-site for two days, and the distance makes returning home impractical. Reasonable hotel costs and business travel costs can be defensible. If you add two extra leisure days, you should expect to separate the costs between business and personal time.

Example 4: On-site lunches every day
You buy lunch near the client premises daily. Even though you’re working, the meal is likely to be considered a normal personal expense unless there is a specific reason it is an additional cost created by business travel. Claiming daily lunches can create a risky pattern.

Industry-specific costs on client premises

Different professions incur different on-site costs. Here are a few examples of expenses that can be strongly linked to client-premises work, depending on your role:

IT and engineering: cables, adapters, specialist diagnostic tools, security tokens, and compliance software.

Construction and trades: safety gear, tools, consumable materials, equipment hire, and site access requirements.

Healthcare and care services: protective equipment, certain training, professional registration, and specialised supplies.

Creative industries: portable equipment, licensing for software, external storage, and client-specific production materials.

These costs tend to be easier to justify if you can show they are required to deliver the contracted service and are not primarily personal.

What about using the client’s facilities and resources?

If you work at a client’s premises, you may use their desk, internet, printer, or meeting rooms. This doesn’t affect your ability to claim legitimate business expenses; it just changes which expenses you incur. In some cases, it reduces what you can claim because the client is already providing resources that you might otherwise pay for.

For example, if you use the client’s internet all day, claiming a significant additional mobile data plan for “on-site internet” might raise questions unless you have a strong business reason (such as security requirements or unreliable connectivity).

How to keep your expenses defensible without overcomplicating your life

The goal isn’t to claim everything you possibly can; it’s to claim what you are entitled to in a way that is consistent, reasonable, and supportable. A simple approach is to create personal rules you follow every time:

Rule 1: Only claim travel when you can clearly explain why the journey is for business rather than ordinary commuting.

Rule 2: Treat meals cautiously; claim subsistence only when there is a clear additional cost driven by business travel or temporary working arrangements.

Rule 3: For mixed-use items (phone, laptop, car), define and document a sensible business-use percentage and stick to it.

Rule 4: Keep receipts and short notes for anything that might look like personal benefit.

Rule 5: Don’t let small “grey area” claims become routine; routine grey areas are what attract scrutiny.

When you should get tailored advice

Working at clients’ premises can create edge cases, especially if you alternate between short projects and long-term assignments, or if your contract resembles employment in everything but name. If you’re unsure about how to treat travel to a long-running client site, how to handle allowances, or how to apportion mixed-use costs, it can be worth getting advice tailored to your situation.

This is particularly true if your expenses are substantial relative to your income, or if you’re claiming accommodation and subsistence frequently. A small adjustment in approach can make a big difference to how robust your position is.

Practical checklist for on-site workers

To finish, here’s a practical checklist you can use to keep your expense claims sensible when you work from clients’ premises:

1) Identify your base: Where do you do admin, planning, and business management? Keep it consistent.

2) Classify client sites: Are they short-term and rotating, or long-term and regular? Adjust travel claims accordingly.

3) Track travel properly: Maintain a mileage log or travel record that notes the business purpose.

4) Keep subsistence modest and justified: Claim meals only when there’s a clear reason tied to work travel or temporary arrangements.

5) Separate business and personal spending: Use a business account if possible, and avoid mixing categories.

6) Document mixed-use items: Keep a reasonable apportionment method and apply it consistently.

7) Keep contract and onboarding requirements: If the client requires certain insurance, training, or equipment, keep the evidence.

8) Be consistent year-round: Consistency is one of the strongest signals that your claims reflect real business practice.

Conclusion

Yes—you can often claim business expenses if you work from clients’ premises. The fact that you work on-site does not stop you claiming costs that are genuinely incurred to deliver your services. In many cases, on-site work strengthens the business rationale for certain expenses like equipment, site-specific requirements, and travel between locations.

The main challenges are travel and subsistence, especially when one client site becomes a regular workplace, and when meals and incidentals begin to resemble ordinary personal spending. The best approach is to apply the business-purpose test consistently, keep good records, and make conservative choices where costs could look dual-purpose.

If you build simple habits—tracking travel, noting the purpose of costs, separating business and personal spending—you can claim what you’re entitled to while keeping your expense position clear, reasonable, and easier to defend.