From ProZ.com Wiki

Overview

Forming a translation company (translation agency) is not as straightforward as it may at first appear. Essentially a translation company is a business venture, and, as such, has little in common with the business of a professional specialist (e.g. translator). However, it is a unique kind of business, and will be most successful when accompanied by an in-depth understanding of the work of a translation specialist.

Some factors to be taken into consideration:

Language questions:

1) How many languages are you going to offer? In other words, what will be your target market? 2) How many languages do you personally understand, to any degree? 3) How many different alphabets can you read? 4) Do you already know any translation specialists? If not, how are you going to find them, check that they produce reliable quality, and build up a database of them? 5) Will you have the facilities or ability to prepare Word documents for translators from poor quality image originals, whatever the language may be? 6) Are you planning to work towards obtaining quality standards certification? If so, how will you achieve it?

Commercial considerations:

1) What is your start-up capital? Is it sufficient to pay all the translators on time, while waiting for your first clients to think about paying your invoices at leisure? 2) Will you need office premises, so that clients can bring you their documents in person? 3) How are you going to organise your business in terms of translation software? What will be the initial costs of a complete set of hardware and software for the company? Have you attended a training course to familiarise yourself with the translation software?