Establish the right requirements first
Use the handbook, manufacturer or an appropriate workshop to confirm the schedule for the engine, year and configuration. If the car uses a variable regime, ask how that regime applies to it. A generic interval copied from another model can give a false picture.
Avoid inferring a universal annual or mileage interval from a badge alone. Additional items may have their own requirements, and an oil-service entry may not describe them.
Put dated readings side by side
For each service, keep its date, reading and units. Compare the chronology with available MOT mileage and the current reading recorded at viewing. Explain a unit conversion separately rather than changing the original source.
For example, an invoice dated 10 April with 40,000 miles and a later MOT at 45,000 miles establish two historical readings. They do not tell you the odometer today or whether another service has happened since.
A dashboard reminder is not proof of completed work
Ask for the invoice or record that supports a service reset. Equally, a warning may need interpretation by the relevant workshop. Keep the question of what was recorded separate from what the current indicator displays.
Use reminders as a diary aid
My Garage can store service dates and mileage thresholds. Mileage logic depends on readings you record; FMSH does not receive live vehicle telemetry. Reminder email delivery is not active yet, so retain your existing diary process.
When the mileage changes, update the recorded reading and check the confirmed schedule. A reminder is there to help organise maintenance, not certify that the car is compliant with a schedule.