Can the employer refuse to reimburse the amounts through them if they are unable to do so, given that the amounts might be significant and could pose a problem for smaller companies?

Since the law does not impose a penalty if an employer refuses to accept the declaration for tax relief for children or children with disabilities, it is possible that such a situation could occur without specific adverse consequences for the employer. However, the employer’s refusal does not deprive the individual of their right to claim the relief – they can still do so by submitting their annual tax return.