According to NCC Twitter handle, the implementation has began and customers can now enjoy a grace period of 7days to use their data plans before it expires.
2. Issuance of Direction to Service Providers on Data rollover which now enables consumers to roll over unused data for 1- 7 days depending on your data plan. This takes effect from 26th of June, 2018.
— ncc.gov.ng (@NgComCommission) June 21, 2018
MTN being the latest telecom with a large subscribers has quickly implement it and you can enjoy your unfinished data plans within the grace period of 1-7days depending on your MTN data bundle.
How Does The Grace Period Work
Daily Plans: If you subscribe to MTN daily DataPlans, you have a grace period of 1day to use your unsed data plans
Weekly Plans: You have a grace period of 3days to use your unfinished data
Monthly plans:You have a grace period of 7days to use your unfinished data
Note: During this Grace period your data plans is expected to work normal. This is the latest development from MTN according to NCC Directives we are wait for other telecoms to implement it also.