Expenditure on designing and developing websites qualifies for capital allowances if the website is used as an on-line shop rather than simply as a way of promoting the business. If the latter applies then you can
claim 100% of the costs as a trading expense in the same year
anyway. Website maintenance is usually regarded as a trading
expense so it is important to distinguish between development and
maintenance costs. The latter includes search engine optimisation,
fixing errors, PPC management, adding temporary features and
updating site content.