投标一词一般译为“tender”，对应的投标人为“tenderer”，如：

When invited to tender, each tenderer may be able to discover the number (and, possibly, abilities) of the competing tenderers. If so, he may compare the benefits of being awarded the contract with his estimated tendering costs and chance of success. These costs may be substantial for Contractor-designed Works, particularly if the Employer requests tenderers to submit extensive details of their designs.

当被邀投标时，每一投标人可能会发现竞标人的人数（可能还有能力）。如果这样，他就可以被授予合同的获利与估计投标成本和成功的机会进行比较。对承包商设计的工程，尤其当雇主邀请投标人提交其设计的深入细节时，这些成本可能很高。

投标邀请函则为“Letter of Invitation to Tender”或“Letter of Invitation”：

相关双语模板如下，供参考：

Letter of Invitation

邀请函

We confirm having advised you that [or: we are pleased to notify you that] you have been prequalified [or: you have been selected as a prospective tenderer] for the above Contract.

我们确认已通知你（或：我们很高兴通知你）你已通过上述合同的资格预审（或：你已被选为预期投标人）。

The Government of ... has received [or: has applied for] a loan from the ... towards the cost of the above project. Part of the proceeds of this loan shall be used for the payment to the Contractor under this Contract, the other parts being used to finance other contracts included in the project.

……政府已从……收到（或：已申请）以上项目费用的贷款。本贷款的部分收入将用于根据本合同向承包商的付款，另外部分用于支付项目中包括的其他合同。

We have appointed as the Engineer [EPCT: as the Employer’s Representative]:

我们已任命……作为工程师（EPCT：作为雇主代表）：

They will soon be issuing,on our behalf, the Tender Documents listed in Clause 1 of the Instructions to the Tenderers.

他们不久将代表我们发出投标人须知第1条所列的招标文件。

We now invite you to submit a Tender in accordance with the instructions to Tenderers which form the first part of these Tender Documents. In the Instructions, the following details are stated to be included in this Letter of Invitation:

现在我们邀请你按照将形成这些招标文件第一部分的投标人须知提交投标书。须知中将对本邀请函包括的下列内容详细说明。

(a) Clause 2 refers to the eligibility of the above-named entity, to whom this letter is addressed;

第2条提到本函收信人上述提名的实体的合格情况；

(b) Clause 3 refers to requests for clarification being sent to the Engineer [EPCT: the Employer’s Representative] who is named above;

第3条提到送给上述提名的工程师（EPCT：为雇主代表）的澄清的要求；

(c) Clause 4 refers to a joint site visit by representatives of the tenderers, and we recommend that you send either one or two representatives to the site for this visit. It will commence at...

第4条提到由投标人代表联合现场视察，我们建议你派一两名代表到现场视察，视察将在……开始；

(d) Clause 6 refers to the submission of your Tender, which must be received at the address stated in the Clause not later than 10:00 on the Tender submission date of ...

第6条提到你的投标书的提交，必须在投标书提交日期……日10时前在本条规定的地址收到。