Русско-англо-русский юридический словарь

Retainer. A fee that the client pays upfront to an attorney before the attorney has begun work for the client. (Wex legal dictionary)

Upfront Fee. A fee paid before a good is produced or a service is performed. The upfront fee is generally a portion of the total fee that the buyer must pay. For example, one may commission an artist to paint a portrait and pay a 20% upfront fee, paying the remainder when the portrait is finished. It is also called an advance fee. (Farlex Financial Dictionary)

What is buyer-funded development?

It is an increasingly popular model of financing property developments by using deposits from many individual buyers. Apartments are sold off-plan to buyers, often overseas, who pay substantial deposits of up to 80% upfront. Their money is used to fund the entire project, from marketing fees to construction costs. (The Guardian)

He added: "Adopting simple procedures such as agreeing payment terms and conditions upfront or using incentives for early payment can have positive effects." (BBC)