Ensure you have an accurate record of your absences over the qualifying period (usually 5 years). You must not exceed 180 days’ absence in any 12 month period but remember that only whole days outside the UK are included in the calculation. If you can’t recall your absences from the UK, you can request a DSAR from the Home Office to obtain this information but this may result in delays.
Helpfully, absences for dependant children aren’t counted so you only need to consider your absences and the absences of any dependant partner.