UK company may opt to register for VAT voluntarily any time. However, some companies would wait until their sales reach the VAT registration threshold.
Generally, once you have registered for VAT, you must add 20% on top of your usual selling price.
When to register for VAT
If you already foresee your company is likely to make sales exceeding the VAT threshold in the first year of trading then you opt to register for VAT straight away.
HM Revenue and Customs requires companies to apply for a VAT number within one month of your company’s sales exceeding the VAT registration threshold.
VAT registration administration
You must put in place a proper VAT accounting system to record your VAT transactions.
For example, the information you must enter into your sale invoice from your sales transactions. There are many easy ways to manage this. You may use online accounting software which comes with VAT invoice template. All you have to do is to fill in the information. The best part is that if you forgot any important details the software will prompt you to enter it. GOV.UK website recommends commercial software that meet the VAT return accounting.
Correspondingly, your company must submit VAT returns with HM Revenue and Customs. Usually, the submission deadline is within one month from the end of your VAT return quarter. The submission must be done online.