An employer should accept a GP fit note as genuine evidence of sickness or injury, unless there is concrete evidence that strongly suggests that your illness is not genuine (for example, a Facebook post on the day you claim to be off sick with flu, showing you at a football match).
Pretending to be ill when you are not would be misconduct and if discovered, is likely to have disciplinary consequences.
Even if all your sickness absences are genuine and certificated, you can still be given a formal warning because of high levels of sickness absence. If the problem continues, you can eventually be fairly dismissed.
However, your employer must act fairly in dealing with poor attendance levels linked to sickness, and this normally means that before dismissing you, your employer should, for example:
- make sure they follow their own attendance procedure properly, including any absence 'triggers';
- get a medical report from an occupational health professional so as to understand the causes of the absences. It is sometimes possible to dismiss fairly for frequent absences without a medical report, but an employer who does this risks a claim for disability discrimination if you have an underlying disability;
- look at your whole employment history and discuss the reason for the absences with you, as well as looking at ways in which you could be helped to turn the situation around. If the situation has suddenly deteriorated, there may be a short term explanation such as illness or family breakdown; and
- look at the impact of your absences on the rest of the workforce and on the ability of the business to function effectively.
To claim unfair dismissal you need two full years' service.
Your employer needs your written consent to collect medical information about your condition. You don't have to agree, but if you refuse, you could make the position worse because your employer will be able to make a decision without the benefit of any medical input.
You are entitled to be accompanied by a trade union rep or work colleague to any meetings that could result in a formal warning for poor attendance. You must also be allowed to appeal against the warning.
You should be given details of all your absences long enough in advance of the meeting for you to be able to check them and compare them with your own record and to make notes of the reasons why you were off work.