Attach Rate

Attach Rate is the percentage of bookings that include at least one paid add-on — breakfast, parking, early check-in, a room upgrade, a transfer, a spa slot or any other ancillary product. It measures how effectively a property or platform converts a confirmed reservation into incremental revenue, and it is tracked per product, per channel and per segment rather than as a single number.

Formula

Attach Rate = (Bookings Containing the Add-On ÷ Total Eligible Bookings) × 100

Revenue impact is usually expressed alongside it:

Ancillary Revenue per Booking = Attach Rate × Average Add-On Value

Example

A hotel receives 1,200 reservations in a month and sells 264 paid parking spaces to those guests.

Attach Rate = (264 ÷ 1,200) × 100 = 22%

At an average parking price of €18, that contributes 0.22 × €18 = €3.96 of ancillary revenue per booking, or €4,752 for the month. Moving the attach rate from 22% to 30% adds roughly €1,700 without a single extra room night.

Attach rates vary sharply by channel: direct bookers, who complete the reservation on the hotel's own booking engine and receive pre-arrival emails, typically attach add-ons at multiples of the rate seen on OTA reservations, where the hotel often has no contact with the guest until check-in.

Why it matters

Ancillary revenue carries far higher margins than room revenue and no distribution cost when sold directly, so a few percentage points of attach rate can move profitability more than an equivalent ADR increase. Because the guest has already committed to the stay, attach-rate improvement is also cheaper than acquisition — there is no media spend and no commission attached to the incremental sale.

Tracking attach rate by channel exposes where the hotel has, and does not have, a relationship with the guest. A large gap between direct and OTA attach rates is a concrete, quantified argument for investing in pre-arrival communication and for negotiating better guest-contact terms with intermediaries.

Related

• Ancillary Revenue — the revenue attach rate is designed to grow
• Upselling — the practice that drives attach rate upward
• ECI / LCO (Early Check-In / Late Check-Out) — among the most commonly attached products
• TRevPAR — the property-level metric that improves as attach rates rise
• Attribute-Based Selling (ABS) — an approach that turns attributes into individually attachable items