Should I keep a written dua list?

Is it allowed?

Yes. Dua has no fixed list or required wording outside the prayer, so writing down what you want to ask is simply a memory aid, like writing a shopping list. Allah invites you to ask Him for anything good:

The Prophet ﷺ said, "Dua is worship" (Sunan Abi Dawud 1479). A list just helps you do more of that worship. Reading duas from a phone or paper is fine too. See Can I read my duas from my phone or a paper?

Why a list helps

• You don't go blank. Many people raise their hands at a blessed time and suddenly forget everything they wanted to ask.
• You remember others. When you pray for someone in their absence, an angel says, "And for you the same" (Sahih Muslim 2732). A list makes sure friends, family and people who asked you for dua aren't forgotten. See Can I make dua for someone without telling them?
• You notice answers. Ticking off duas that were answered, sometimes years later, builds gratitude and trust in Allah.
• You balance your requests. Seeing the list reminds you to ask for the Hereafter, not only for jobs and exams.

How to organise it

• Start with praise. Open with praising Allah and sending salawat on the Prophet ﷺ.
• Your own needs: faith, forgiveness, health, work, family, studies.
• People: parents, spouse, children, friends, non-Muslim relatives (for guidance), the sick and the deceased.
• The Ummah: people in war, hunger or hardship.
• Quran and sunnah duas you're learning, with transliteration and meaning.

Use it at the times dua is most hoped to be answered. See What are the best times to make dua?

Keep the heart in it

The one risk is turning dua into reading a checklist. Scholars warn that a dua from a heedless heart is weak. So slow down, mean each line, and feel free to stop and add something in your own words. Your list serves your dua; it doesn't replace it.