break up fee指的是分手费，也称终止费。

分手费是买方的防御性措施，指卖方如果退出交易，则应当支付一定费用给买方，一方面用以补偿买家用于促成交易所花费时间和成本（在尽职调查和谈判阶段耗费了大量时间和资源，包括但不限于聘请法律、税务及会计顾问费用及开支），另一方面也可以反映出卖方合作的意愿。

A Breakup Fee, also referred to as a termination fee, is a penalty that is paid in mergers and acquisitions transactions if the seller backs out of the deal. The fee serves to compensate the purchaser for the time and resources spent in negotiating the deal.

reverse break up指的是反向分手费。

反向分手费，又称为反向终止费，相对于分手费，卖方通常通过反向终止费分手费作为保护措施，因买家原因或其他约定原因发生，导致买家放弃交易或交易无法进行，由购买方向卖方支付的分手费。跨国并购不仅涉及经济、管理问题，而且也会涉及到文化层面、甚至政治等敏感因素，政治审查、反垄断调查往往被用作针对性的保护政策。尤其当交易一方中涉及到中国买方，前述各种因素导致交易不确定性的几率往往更高，因此卖方会在协议中要求设置反向分手费作为救济，允许卖方在因买方原因终止交易的情况下收取费用。

A reverse termination fee is also known as a reverse breakup fee. It refers to the amount of money paid to the target company after the acquirer backs out of the deal or the transaction fails to complete. Usually, the reverse termination fee is included in the acquisition agreement, and it can be triggered when the acquirer is unable to obtain the required financing to close the transaction. The purpose of the reverse termination fee is to compensate the target for its time and effort in facilitating the transaction.

以下为相关双语示例，供参考：

If its credit rating drops sharply, the banks have the right to revoke the loan—and Wyeth could walk off with a $4.5 billion break-up fee.

如果辉瑞的信用评级急剧下滑，银行有权收回贷款——惠氏公司则可以拿着45亿美元的协议终止费全身而退。

If the deal is blocked, it will get a break-up fee of $3 billion, a chunk of spectrum and a favourable roaming agreement.

如果这笔交易被叫停，它将得到一笔30亿美元的分手费，一大块频段以及优惠的漫游协议。