Things to keep in mind when you hire a professional company:
Turnaround time
You must check what turnaround time is promised by the company. Keep a buffer of a few days before your submission to make sure that you do not miss your deadline.
Originality
Since all dissertations must be 100% original and plagiarism free, this is an important factor to check before you finalise the company. They must assure originality in all the content.
References
Many times, students are confused about choosing good and new references. Pick a company that will help you in selecting the latest references and create a better literature review as well
Citation styles
If you are writing a dissertation for the first time, you might be unaware of the various citation styles, thus leading to loss of marks. Choose a company that guarantees 1005 compliance with the necessary citation styles.
It may be a tough choice to make, but choose wisely to ensure that your dissertation is in good hands so that you can score well in your dissertation and succeed in your future.
Good luck!