The change was first proposed in January when a consultation was launched about toughening the regulations surrounding track limits.
Instead of the existing rule of an offence being committed if "any wheel of the car goes completely beyond" white lines or the edge of a kerb, it was suggested the definition should change to be "any part of the contact patch of the tyre goes beyond either the outer edge of any kerb or the white line where there is no kerb".
This has now been approved by the Motorsport UK board and will be effective from next weekend.
However, plans to significantly alter the penalty system – including introducing a one-second time addition for the first offence – have been dropped following the consultation.
Motorsport UK CEO Hugh Chambers has written to all race licence holders on Thursday explaining the new rule and the reasoning behind making the change.
As part of the letter, Chambers said that the rule tweak has arisen following a wider review of driving standards and a belief "there is less than a universal understanding of where the limit of the track lies".
"The track limit is there for very good reasons, safety and fairness," he added.
"In regard to safety, the track licence that is provided by Motorsport UK considers all of the safety measures in place at a track and in particular the run-off areas on any part of the circuit including the physical interventions that are in place to minimise any impact.
"Without track limits regulations and enforcement, the circuit owners are in an impossible situation.
"In the interests of minimising damage to vehicles, the governing bodies of both car and bike racing have reduced permissible physical deterrents to going beyond track limits – and the circuits understand this.
Source: Autosport