Bilheteria vs. bilheteira
The words bilheteira and bilheteria both correspond to the English terms "ticket office" or "box office". The primary distinction between them is geographical: one is standard in European Portuguese, while the other is standard in Brazilian Portuguese.
Bilheteria
A2This form is used exclusively in Brazilian Portuguese. It refers to the physical booth or window where tickets are sold. Additionally, in Brazil, bilheteria is commonly used to describe the financial revenue generated by a movie or theatrical production (box office numbers).
A bilheteria do cinema abre às duas da tarde.
(The cinema ticket office opens at two in the afternoon.)
O novo filme de super-herói foi um sucesso de bilheteria.
(The new superhero movie was a box office success.)
Você precisa ir até a bilheteria para trocar o voucher pelo ingresso.
(You need to go to the ticket office to exchange the voucher for the ticket.)
Bilheteira
A2This form is used in European Portuguese (Portugal) and other Portuguese-speaking countries in Africa. It refers to the counter or office where tickets are sold, particularly in train stations, theaters, or stadiums.
A fila para a bilheteira na estação de comboios estava enorme.
(The line for the ticket office at the train station was huge.)
Dirija-se à bilheteira central para comprar o passe mensal.
(Head to the central ticket office to buy the monthly pass.)
Encontramo-nos junto à bilheteira do estádio antes do jogo.
(We will meet next to the stadium ticket office before the game.)
Summary
To choose the correct word, consider your audience. Use bilheteria for Brazil and bilheteira for Portugal. While both refer to the physical location of ticket sales, recall that the Brazilian bilheteria also frequently refers to the earnings or popularity of a show.