Every multistate practitioner knows the drill: a client operates in six states, and a simple question — when are estimated payments due, what's the filing form, is there an automatic extension — turns into an afternoon of tab-hopping across state revenue department websites, each organized differently, each answer copied into a spreadsheet that's outdated the moment it's finished. Today we're shipping the tool we wished existed: the State Tax Matrix, now live in PartnertaxAI.
One table instead of fifty tabs
The matrix puts the states you choose side by side in a single table. Pick an entity type — partnership, corporation, or individual — then select any combination of states and the attributes you want to compare: filing forms, tax rates, due dates, extension deadlines, estimated payment schedules, and more. Comparing two states in depth or scanning all fifty at once are both one selection away, and you can flip the layout — states as columns or states as rows — to whatever reads best for the comparison at hand.
Every cell shows its work
A comparison table is only as good as its sourcing, so the matrix works the same way our AI Tax Assistant does: every cell carries a citation to the authority it came from, and hovering shows the exact passage behind the value. Treat the table the way you'd treat any research draft — the citations are there precisely so you can verify each answer against its source before relying on it, and that check takes a click instead of a research session. Where an entry doesn't yet cite a source, it's labeled as such rather than hidden.
From comparison to advice in one click
A table tells you what the rules are; the interesting question is usually what they mean for your client. That's why the matrix is wired directly into the AI Tax Assistant: any row — or the whole comparison you've built — can be handed off with one click, arriving as a fully-formed question about the differences and planning considerations across your selected states. The research context you set up in the table carries straight into the conversation.
Try it
The State Tax Matrix is live now in PartnertaxAI — sign in and you'll find it in your workspace sidebar. If you spend any part of your week reconciling state-by-state differences, this is the view we built for you. Start comparing at partnertax.ai.
Shashank Sharma is the founder of Partnertax.ai, an AI tax assistant for tax professionals, built on cited IRS and Treasury sources.