Send us a message whenever you like. We scan our inbox for urgent queries throughout the day, and for general queries you'll get a response in 24-48 working hours. if it gets to 72 working hours and we still have not been able to answer your question, we'll explain why, e.g. more research required, waiting on HMRC, etc. Note, we do not in general send acknowledgement emails as this uses up time that could be better spent working on queries and handling accounting; we do ensure every email is answered.