Payment
Although there are several ways to pay for design and development services, most web projects require a deposit and subsequent payment(s). A web design/development contract should outline what is payable—and when it is due. It legally commits both parties to the project, preventing the web designer from pulling out—and the client from stopping the project and refusing to pay for the work done thus far.
Copyright
Contrary to popular belief, in some countries (including the UK) the copyright for design actually stays with the designer by default. What the client pays for is the right to use the commissioned design work in a particular context (i.e. your website). A good web design contract will state in no uncertain terms what belongs to which party. If you don’t wish to be held hostage by your web designer, you should ask him or her to include transfer of the design copyright to you in the contract.
Amendments, Revisions and Alterations
To protect the web designer from doing endless rounds of edits, a contract will cap the number of design/development iterations and time spent on amendments. This is beneficial for the client as well, as you are aware from the outset how much time you have to work with and how many rounds of revisions you are allowed within the context of the contract without additional billing.
Supplying Content/Errors in Content
A contract should also make the client agree to exercise due diligence when writing text and providing content and images for the site. They must be able to substantiate all claims and representations and be responsible for all trademark, copyright, etc.
If you are being trusted to manage some of the content for the site via a CMS, then the web designer will use the contract to make you responsible for any content you add. Many times, a contract will include a clause about additional costs involve if something you, the client, updates that causes damage to the site design. Please be aware of this possibility when you are making your own updates.
Maintenance, Support and Backups
Once the site is live, who is responsible for maintaining the site, backing it up and offering support? Don’t assume that you can rely on your web designer free-of-charge indefinitely. Agree a post-launch plan with your web designer and pay for it accordingly. This plan may be included in your original contract, or in a post launch contract specific to maintenance and support.
Do you need a contract? Yes. It protects your web designer as your service provider, and more importantly, it protects you.