Do I have to declare the earnings I receive as part of the Accorhotels.com affiliation programme to the tax authorities?
Yes. You must declare all your income to the tax authorities. In any instance, it is always a good idea to seek the advice of legal counsel or of the relevant administrative service to find out exactly what the rules are that apply to your particular situation, in particular if your affiliate activity grows fast and/or it is or becomes your main business.