Sometimes children will see parents or other role models lie without apparent consequences. Thus lying behavior is copied. Establish guidelines in your house about truth. Discuss moral issues and explain to your school-age children why we don't lie. Swift, meaningful and consistent consequences must be carried out by the parent when a child does lie.
All children lie but in most, it is infrequent.
Though lying behavior evokes intense emotion in most parents, avoid over-reaction and severe consequences. Demonstrating to the child that telling the truth about a previous misbehavior will lessen the punishment is not compromising your parenting values. Accidentally breaking a treasured dish due to prohibited rough-housing is not good. Punishment or restitution must occur. But if the child can admit the misdeed, some mitigation will help the child tell the truth in the future.