advance在法律文件中常见的含义有2个：

(1)预先，如pay in advance预先付款；

(2)垫付，如money advanced for sb. to be paid back later暂替他人垫付钱款。

而prior to，在......之前，其含义更接近"before",如Prior to or on the Completion Date, the Buyer must provide the Sellers’ Representative with......，其与advance区别较大，如advance payment预付款，payment prior to delivery交货前付款。

1预先

No amounts are presently owing to any Group Company as a result of any loan or advance made by any Group Company prior to the date of this Agreement (otherwise than as a result of giving credit in thenormal course of business).

目前不存在由于任何集团公司在本协议签订之日以前提供的任何贷款或预付款而欠付任何集团公司的任何款项（由于在正常业务过程中给予的信用额度产生的除外）。

2垫付

Client agrees that it will be responsible for payment of Additional Expenses, though CT may from time to time advance such costs.

客户同意，尽管CT可能不时垫付额外费用，将由客户最终负责支付该额外费用。