You must claim the allowance for sickness expenses yourself when you submit your tax return.
You must also be prepared to document/substantiate all the expenses for which you are claiming an allowance if the tax office asks you to.You should therefore retain receipts, vouchers, etc. that are linked to the expenses you believe you are entitled to an allowance for. Even if your expenses are difficult to document, you will still be able to claim an allowance for your expenses if the tax office considers it overwhelmingly likely that you have incurred them. For retrospective added expenses in connection with a sickness which are difficult to document, substantiation of your added expenses for a continuous, representative period during the income year (at least one month) may be sufficient to substantiate that they were incurred over the entire income year.
A completed form prepared by a stakeholder organisation will not automatically be considered sufficient documentation/substantiation of your added sickness expenses. However, such forms can provide some guidance in relation to your expenses which can be attributed to your sickness either directly or indirectly.