Airbnb sometimes charges taxes on the Host Fee.  This is based on the tax jurisdiction the property finds itself in and the way they setup taxes within Airbnb.

In each booking message, there may be two 'negative' charges (ie, bring down teh total income for the booking) that get applied to the folio when the property is booked:  1) host_fee_base and 2) host_fee_vat

• Airbnb’s host_fee_vat field is the VAT charged on Airbnb’s host service fee itself, not a tax on your payout or on the guest stay.
• In other words, from a US accounting perspective: Total Airbnb fee expense = host_fee_base + host_fee_vat

For accounting, most hosts treat:

• host_fee_base as an expense (Airbnb platform/service fee)
• host_fee_vat either as VAT on purchased services (potentially recoverable input tax if you are VAT-registered and local rules allow) or as part of the expense if you cannot reclaim it.

Why VAT shows up on a USA listing

• Airbnb is a non‑US entity for many of its platform operations and is required in various countries to charge VAT on its service fees for electronically supplied services.
• That VAT obligation depends on Airbnb’s place of supply rules, not your property location, for example in Texas where there is no VAT government tax, so the VAT is Airbnb’s tax on the fee it charges you, not a US‑state tax.
• Airbnb issues VAT invoices when this applies and breaks out the VAT amount separately; your API’s host_fee_vat mirrors that breakdown.a

So even though the property is, for example, in Texas, host_fee_vat is best understood as a non‑US VAT on Airbnb’s own service fee, passed through and itemized to the folio.