When Statutory Sick Pay ends
SSP stops when you return to work, when your employment ends, when you are no longer eligible, or when you have been paid SSP for 28 weeks in the same period of incapacity for work (including linked periods). Acas explains the 28-week limit and linking.
Two spells of sickness are linked if the gap between them is 56 days or less. The rate and the 28-week clock are taken from the start of the first spell, not the later one. If you have already used some of the 28 weeks in a linked spell, enter those qualifying days in the calculator so the cap is applied correctly.
When occupational sick pay runs out before week 28, you may still get SSP on its own. When SSP also runs out, this calculator shows no further sick pay. You may be able to claim benefits. That is not something this tool estimates, because it would be personalised benefits advice. Start with GOV.UK benefits or a welfare-rights service.
If your employer thinks you are not eligible, they should tell you why, often on form SSP1, which you may need if you claim benefits.