Find your form. To search, type in a keyword and/or choose a category. To search for archived forms from a previous tax year, choose a year in the drop down menu.
So don't worry so much about how to use  had had  as a unit of grammar, they will come together naturally when you want to express the verb ' to have ' in the past perfect. Let's consider a different verb for a moment like  to want .
(followed by âtoâ without a verb in the infinitive): Weâll fight for our rights if we have to. This use of have can be in the progressive: I was having to work every weekend. Have got to is often used instead of have to, especially in spoken English and in informal writing: Youâve got to show your passport.