Ordinarily the LTA would suggest that at grade 1 – 5 competitions a court supervisor, tennis leader or club volunteer is engaged to support you in scoring. However, for local, club, or informal events bringing a friend or family member along may be allowed. This will help some players cope with the stresses of the competition environment but additionally, if you struggle to keep score, you can have someone on-site to help you with this.
Any guest brought to the match cannot interfere with the game of tennis and must only be there for support. Unless helping with scoring, any guests must stay off court and not interfere with play. If you need someone to help you keep score, they can stand courtside, and the tournament organiser/referee will let your opponent know in advance. The person keeping score should only shout out the score, they must not interfere with calling lines or any other on court matters.