You need to estimate the accommodation cost for an employee sent on a three-week assignment in Martinique, Guadeloupe or French Guiana, and you want a reliable budget before committing the expense. Between a hotel billed per night, a holiday rental in a private individual’s name, and para-hotel accommodation invoiced in the company’s name, the differences in cost and accounting compliance are significant. This article offers a simple, repeatable calculation template, with indicative ranges suited to the French Caribbean and Guiana, so that your expense report goes through without friction and your cash flow stays under control.
The amounts mentioned below are orders of magnitude intended to help you build your own estimate. Actual rates depend on the season, the island, the location and the length of stay: always request a firm quote before validating a budget.
The cost items of a 3-week assignment
A long assignment is not just about the price per night. To avoid unpleasant surprises at the end of the month, you need to break the budget down into distinct items. Here are the lines to include in your template:
- Accommodation (main item): the rent or per-night rate over 21 nights.
- Charges included or not: electricity (air conditioning is power-hungry in the tropics), water, internet, cleaning.
- Additional costs: household linen, parking, possible tourist tax.
- Meals: an equipped kitchen on site or daily outside dining.
- Mobility: proximity to the assignment site, the cost of a rental car if the accommodation is isolated.
The major difference between a hotel and furnished para-hotel accommodation lies in these additional charges. A hotel room has a per-night rate that climbs quickly over 21 nights, but it often includes daily cleaning. A long-term furnished rental offers an attractive degressive rate, with a kitchen that greatly reduces meal costs, but you need to check what is included in the price.

Calculation template: the basic formula
For a 3-week stay, the formula fits in a few lines. It is based on a degressive daily rate specific to long-term stays, very different from a short-stay per-night rate.
The formula
Accommodation cost = (long-term daily rate x 21 nights) + charges not included + additional costs (cleaning, linen, tourist tax).
The key point of the calculation: over a 21-night assignment, you do not reason at the weekend or short-stay rate. Business accommodation applies a degressive monthly or weekly rate, which can represent a significant reduction compared with adding up 21 nights at the full rate.
Indicative worked example (ranges)
Purely for guidance, for a decently appointed furnished studio or one-bedroom flat in the French Caribbean and Guiana:
- Long-term furnished accommodation: 1,400 to 2,800 EUR for the 3 weeks.
- Electricity / air conditioning: included, or around 150 EUR if extra.
- End-of-stay cleaning: 50 to 120 EUR.
- Linen, sheets, towels: often included.
- Tourist tax (if applicable): varies by municipality.
These ranges cover the diversity of situations between a French Guiana where supply can be tighter and a French Caribbean where the high tourist season (December to April) pushes prices up. Always compare with the cost of an equivalent hotel room over 21 nights, often clearly higher once breakfast and meals are added.
Why para-hotel accommodation changes the accounting calculation
Beyond price, it is the compliance of the expense that distinguishes professional accommodation from a rental between individuals. A classic holiday rental in a private host’s name often leaves you with a simple receipt, hard to justify in accounting and with no recoverable VAT.
Para-hotel accommodation, on the other hand, works like a service provider: invoice in your company’s name, full legal information, payment by bank transfer and, depending on the applicable regime, VAT charged. This is what turns a fragile expense into a fully justified charge.
Invoice in the company’s name
The invoice issued in the company’s name (registered name, business registration number, address) is the document that secures your expense report. It allows the accountant to attach the expense to the right cost centre and record it as a charge without question during an audit.
VAT and payment by transfer
Depending on the applicable para-hotel regime, the service may be subject to VAT, potentially recoverable by the liable company. Payment by transfer, unlike settlement on the employee’s personal card, avoids the employee fronting the costs and makes bank reconciliation easier. Always check the VAT regime on the quote, as it determines the real net cost for the company.
Compliant expense report: what you need to gather
A rejected expense report means an unreimbursed advance for the employee and a non-deductible charge for the company. To avoid this on a long assignment, gather the supporting documents from the moment you book.
- Invoice in the company’s name (correct registered name and registration number)
- Stay dates covering the exact duration of the assignment
- Breakdown of services (accommodation, cleaning, charges) line by line
- Mention and rate of VAT where applicable
- Proof of payment by bank transfer
- Assignment order or evidence of the professional purpose
- Contact details and legal information of the provider
This file constitutes the trail needed for the expense to be accepted without discussion. Keep it with the assignment order: the link between the accommodation and the professional purpose is what the tax authorities check.
