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Context is a "Política de viajes y presentación" - Spain Spanish. The document is from Pfizer (pharmaceutical company).

In it there are two abbreviations I'm unable to find anywhere. The first is

BU/Dpto.

I'm assuming Dpto. = Department (Dpt.), but I'm stumped on the BU part. It occurs only as follows:

Empleados BU/Dpto
Directores BU/Dpto (C3)
Country Council Committee - Todos los Directores de BU / Dpto en España


The other is BTA.
For this one it says - Todos los viajes de aquellos empleados que no dispongan de tarjeta corporativa, deberán cargarse a la BTA del departamento correspondiente.

Some of the abbreviations in the document are in English, and some in Spanish, So I'm not sure if this is an English abbreviation or not.

Any help would be much appreciated. Many thanks!