In recent months, we have been seeing a clear pattern in limited inspections and audits: The tax authorities are rejecting travel expenses that companies considered to be well-justified. Not because the expenses did not actually occur, but because the documentation does not exactly meet the criteria required by the tax authorities.
Receipts, invoices, and expense reports aren’t always enough. When there is no clear travel authorization, no specific link to a project, or a lack of consistency among the documents, the result is usually the same: adjustments, interest, and, in some cases, potential penalties.
And the worst part is that many of these mistakes are completely avoidable.
In this guide, we explain—using real-life examples—what the tax authorities consider to be travel expenses, what limits they apply, what documentation they accept, and how to set up an internal system that can withstand an audit without any issues.
Why So Many Companies Have Problems with Travel Expenses (and How to Avoid Them)
Imagine that your sales representative returns from Valencia with receipts and invoices. Months later, the tax authorities review the documents and disallow part of the expenses because they cannot reconstruct the “history” of the trip: who went, what the purpose was, for which client or project, and what supporting documentation was provided.
It’s not the spending that’s the problem—it’s the test.
The good news is that this can be avoided with a simple procedure: (1) prior authorization or order, (2) a clear timesheet from the employee, and (3) supporting documentation and records of activity (calendar, CRM, work report) that all tell exactly the same story.
Let’s go through this step by step, using real-life examples.
What does the tax authority consider to be “travel expenses”?
The tax authorities recognize as travel expenses work-related trips made outside the usual municipality of employment that result in transportation, meal, or lodging expenses.
However, during an audit, it is not enough simply for the expense to exist: it must be possible to demonstrate why it was necessary and to which specific activity it is linked.
For practical purposes, the tax authorities distinguish between three types of expenses:
1. Locomotion (movement)
- Train, plane, or bus tickets.
- Mileage in a personal vehicle.
- Tolls, parking, and taxis.
Inspection criteria: The route, date, and destination must match the reason for the trip.
2. Meals (during travel)
- Breakfast, lunch, and dinner.
- Only when the employee is outside his or her usual municipality of work.
Inspection criterion: consistency between schedules, location, and travel time.
3. Lodging (accommodations)
- Hotels and vacation rentals.
- Always in a different municipality than usual.
Inspection criteria: the check-in and check-out dates must be consistent with the work performed.
Key point (this is what determines whether it is accepted or not)
For the tax authorities to accept a travel expense, the trip must meet two conditions at the same time:
- To have taken place in a municipality other than that of the workplace or usual place of residence
- Have a specific, verifiable professional reason (client, project, training, job site, meeting, etc.)
If either one fails, the expense is usually rejected.
The limits on per diems and travel expenses that the Treasury is reviewing during inspections
The tax authorities set maximum amounts for certain travel expenses. When these limits are observed and the trip is properly justified, the amounts paid to the employee are not subject to personal income tax.
If the limits are exceeded, the excess is considered earned income and must be included in payroll.
Locomotion
| Mode of transportation | Limit accepted by the Treasury |
|---|---|
| Public Transportation | Actual ticket price, provided there is a receipt or invoice |
| Personal vehicle | 0.26 €/km plus duly documented tolls and parking fees |
- Inspection note: When using a personal vehicle, the tax authorities typically verify that the route, mileage, and destination are consistent with the reported business activity.
Child Support
| Situation | Spain | Foreign |
|---|---|---|
| With an overnight stay | 53.34 €/day | 91.35 €/day |
| No overnight stay | 26.67 €/day | 48.08 €/day |
- Practical example: An employee travels to Madrid for one day, without staying overnight. The company may pay him up to €26.67 for meals without it being subject to tax. If he is paid €40, the difference of €13.33 will be considered income from employment.
Accommodations
| Type of expense | Limit accepted by the Treasury |
|---|---|
| Accommodations | Actual amount supported by an invoice |
| Accommodations for Truckers | 15 €/day in Spain and 25 €/day abroad |
There is no general quantitative limit on lodging expenses, but the tax authorities verify that the amount is reasonable and related to an actual business trip.
The documentation the IRS requires during audits to accept travel expenses
This is where most companies fall short. It’s not enough to have a restaurant receipt or a hotel bill. During an audit, the tax authorities want to see a coherent set of documents that allows them to reconstruct the trip from start to finish and understand:
- That the displacement took place
- When was it held?
- Where did it take place?
- Why was it necessary from a professional standpoint?
If that “history” cannot be clearly reconstructed, the expense is usually rejected.
1. Travel Order or Work Order
It is the most important document for justifying travel expenses and carries the most weight during an audit. It must be in place before or at the time of travel and must clearly identify who is traveling, when, where, and for what business purpose, as well as the associated client or project and the corresponding internal authorization.
Real-world example of a displacement order:
- Employee: María García
- Date: March 15, 2025
- Destination: Seville
- Reason: Business meeting with client Industrias López SL
- Project: COM-2025-089
- Authorized by: Sales Director
Without this document, the other supporting documents lose much of their probative value.
2. Employee Expense Report or Statement of Accounts
The employee must submit a clear and organized list of expenses incurred, so that the information can be cross-checked against the travel authorization.
It must reflect:
- Origin and destination.
- Distance traveled (if using your own vehicle).
- Expenses: tolls, parking, meals, hotel.
- Amounts.
- Project or associated client.
- Employee’s signature and manager’s approval.
During an audit, the tax authorities pay particular attention to ensuring consistency between this form and the other documents.
3. External supporting documents
They serve as proof of expenditure. The IRS accepts, among other things:
- Airline, train, or bus tickets (paper or electronic).
- Hotel invoices issued in the name of the company or the employee.
- Restaurant receipts or bills (preferably with the customer’s name on them).
- Toll, parking, or taxi receipts.
- Certificates of attendance for events, trade shows, or courses.
- Emails, notices, or invitations confirming meetings.
Practical tip: Keep everything in digital format. A clear photo of the parking ticket may be enough if the rest of the documentation is consistent.
4. Links to Business Activities
This is what distinguishes a business trip from a personal one. The tax authorities want to see objective evidence that the trip was related to the company’s business.
Common documents:
- Business calendar or CRM with the scheduled meeting.
- Work orders signed by the client.
- Visit reports or meeting minutes.
- Work orders related to the project.
Real-life example of a disallowed expense: A company claims a business lunch in Marbella on a Friday. There is no travel order, no documented meeting, and no associated client. The tax authorities disallow the expense because they cannot link it to any specific business activity.
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What if the company pays for the hotel or meals directly?
Direct answer: Yes, this completely changes the nature of the expenditure.
When the company pays the hotel, restaurant, or transportation directly, this is no longer considered a per diem for the employee, but rather an expense borne by the company itself.
This has significant implications during an inspection:
- It is not taxable for the employee, because it is not considered income from employment.
- It is deductible for corporate income tax purposes.
- It is not subject to daily per diem limits, provided that the expense is reasonable and justified.
However, the tax authorities will only accept this treatment if three key conditions are met:
- The invoice is issued in the company’s name (business name and tax ID number).
- The expense is correctly recorded as a company expense (usually in account 629, when it is not employee compensation).
- There is a clear and demonstrable link to professional activity.
Practical example: The company books a hotel in Barcelona for a sales representative. The invoice is made out to the company and is recorded as “other services.” The expense is not taxable for the employee and is deductible for corporate income tax purposes, provided that the business reason for the trip can be justified.
What Each Type of Invoice Must Include to Be Valid
Check-in and check-out dates
Municipality of residence (other than that of the workplace)Consistency with the displacement command
Date and city consistent with the travelClear connection to the purpose of the trip
Date and place of consumptionBusiness reason (client, supplier, project)
Additional support: email, calendar, or CRM
| Type of expense | Minimum requirements set by the IRS | Factors That Strengthen the Justification for an Inspection |
|---|---|---|
| Hotel or lodging | Company Name and Tax ID Number | Enter the name of the employee staying here |
| Taxi, ride-hailing service, or car rental | Invoice (may be a simplified invoice) | For rent: lease agreement + invoice + proof of mileage |
| Restaurants | Invoice in the customer’s name (preferred over a receipt) | Internal Identification of Attendees |
Practical tip: If you have a meal with a client, make an internal note of the reason. For example, on the invoice itself or in a follow-up email: “Business lunch with Juan Pérez (Company X) – Project Y.” These types of notes greatly strengthen the justification for the expense during an audit.
How to Record Each Type of Expense (Accounting Accounts)
| Accounting Account | Type of expense | Tax Treatment | Example |
|---|---|---|---|
| 649 – Other Social Expenses | Per diems and travel expenses that do not exceed the limits established by the Department of the Treasury and are not considered part of salary | They are not taxable for the employee | €50 allowance for meals and lodging in Spain (maximum: €53.34) |
| 640 – Wages and Salaries | Per diem allowances or expenses that exceed legal limits and are considered part of salary | The excess is taxed as earned income for the employee’s personal income tax purposes | €70 allowance for meals and lodging in Spain (excess of €16.66) |
| 629 – Other Services | Company-related expenses (hotels, restaurants, transportation) that do not constitute compensation for employees | Deductions from Corporate Income Tax, if Justified | Hotel bill in the company’s name for a business trip |
This issue is particularly critical in sectors such as the cultural and audiovisual sectors, where many travel, per diem, and lodging expenses are directly linked to projects that take advantage of tax incentives.
In these cases, failing to provide adequate justification for the trip not only puts the expense at risk, but also the incentive itself.
The 7 Mistakes That Cause the Tax Authority to Reject Travel Expenses During an Audit
1. There is no relocation order
Without this document, you cannot prove that the trip was for business purposes. The other supporting documents lose much of their probative value.
2. The date, location, or specific reason is missing
“Trip to Madrid” isn’t enough. The tax authorities require something like: “Madrid, March 15, 2025, meeting with client ABC regarding Project X.”
3. Invoices that do not include the company’s name
Generic receipts that do not include a company name or tax ID number are not valid if the expense is to be claimed as a business expense.
4. Expenses not associated with any project or client
If you cannot prove the purpose of the trip, the IRS will classify it as a personal expense.
5. Mileage not recorded internally
Reporting mileage without a travel log, app, or internal record is insufficient during an inspection.
6. Meals without the required documentation
At a minimum, the date, location, and consistency with the documented travel must be provided.
7. Documents That Do Not Match Each Other
If the travel order specifies Valencia on the 10th and the hotel bill is for Alicante on the 12th, the tax authorities become suspicious and usually reject the expense.
How to Create an Internal System That Works (and Saves You a Lot of Headaches)
You don’t need anything complicated. Just a clear, three-step process:
BEFORE the trip
- Generate a travel order (this could be an internal email, a form, an entry in your ERP, etc.).
- Include: date, destination, reason, project, authorization.
DURING the trip
- Keep track of mileage if you use your own vehicle (app, notebook, Excel, etc.).
- Keep key receipts: hotel, main transportation.
- Keep receipts for miscellaneous expenses: parking, tolls.
AFTER the trip
- The employee submits an expense report listing all items.
- It is approved and signed by the person in charge.
- It integrates with CRM, a calendar, or a project management system.
- Everything is filed together (preferably digitally).
Golden rule: If your documents “tell the same story” and can be cross-checked, the tax authorities usually have no objections.
Conclusion: Justifying travel expenses isn’t difficult if you follow the proper procedure
As we’ve mentioned, most problems with travel expenses don’t stem from the expenses themselves, but from procedural errors.
The Treasury isn’t debating whether the trip was comfortable or expensive, but rather whether it can clearly reconstruct what was done, when, and why.
It’s not about saving every coffee receipt. It’s about:
- Prove that the displacement occurred (displacement order)
- Explain why it was necessary (connection to the activity)
- Respect the limits or correctly report the excess
- Keep key documents (accommodation, transportation, and major receipts)
Although for tax purposes it is not always necessary to keep every individual receipt to justify per diem expenses to the tax authorities, in the workplace, the Labor and Social Security Inspectorate may require them to verify the employee’s living expenses.
For this reason, it is advisable to keep your receipts, label them correctly, and link them to the corresponding trip.
With a straightforward internal system—as simple as a pre-trip form, a clear expense report, and a well-organized digital file—it’s possible to ensure that travel expenses are ready for an audit without any surprises.
Recommended action: Review your most recent business trip and see if you could reconstruct it today using the available documentation. If anything is missing, you’ll know what to improve for your next trip.
Frequently Asked Questions (Answered)
Can I claim the breakfast included with the hotel stay as a deduction?
Yes, but it falls within the per diem limit. If you pay €80 for a hotel room with breakfast included, that breakfast counts toward the €53.34 per day per diem (with an overnight stay).
What happens if the trip is partly for personal reasons?
You can only claim the business portion. Example: a 5-day trip—3 days for work and 2 days for sightseeing. You can only claim 3 days.
Is a restaurant receipt valid without an invoice?
It can serve as a clue, but it’s a weak one. It’s best to always ask for a receipt (even if it’s a simplified one).
Can I claim expenses from a trip I took 6 months ago?
Yes, as long as it’s within the fiscal year and you have the documentation. But it’s best to keep your books up to date.
What should I do if the tax authorities reject an expense during an audit?
Provide all supporting documentation: emails, CRM records, client reports, etc. If you can demonstrate the professional connection, it is often accepted as evidence in your arguments.
