Frequently asked questions

No — and that's intentional. Core Books AI handles the day-to-day: categorization, tax estimates, reports, and the questions you'd otherwise text your accountant at 11pm. Every plan includes accountant access — invite your CPA from settings and they get their own login to review and categorize transactions inside your books. Most users save their CPA hours of cleanup and a chunk of their bill.

Yes. On Co-Pilot and Command you can connect your favorite agent (Claude, ChatGPT, Grok and others) to your books. It can read your numbers, categorize transactions and make rules, and anything you decided yourself only changes if you say yes. Every plan also includes Cash, our built-in AI bookkeeper.

Yes — Core Books AI is live. Sign up, connect your bank, and your books start categorizing straight away. Founding Members can still lock in 50% off the first year on Co-Pilot or Command (annual billing, limited to the first 200 seats). Annual plans are billed up front and come with a 30-day money-back guarantee, so you can try it risk-free. Prefer to pay month-to-month? Monthly plans start with a 14-day free trial instead.

Most accounting tools were built for accountants and adapted for self-employed users — Core Books AI was built the other way around. We're cheaper ($9–$35 vs $30–$200), AI handles categorization instead of brittle rules, tax estimates update in real time instead of quarterly, and you can ask questions in plain English instead of learning their UI.

Cash basis means money counts when it actually moves: invoice paid? Revenue. Bill paid? Expense. It's how most self-employed people already think about money, and how the IRS lets businesses under ~$32M in average annual receipts file. Accrual counts income when you invoice and expenses when you are billed. Every plan keeps cash books, and Command adds a Cash / Accrual switch on your reports, vendor bills, what customers owe you and what you owe vendors by age, and tax estimates on the method you file.

Yes. We never see or store your bank credentials — Plaid handles the bank connection. Your data is encrypted in transit and at rest, and row-level security means only you and the people you invite can read your books. We run on infrastructure from providers that maintain SOC 2 Type II certification — Plaid, Stripe, Supabase and Vercel. And we never sell your data. Period.

Yes. Each business has its own plan and its own books, so an LLC and a rental never mix. Add another company from the business menu, switch between them in one tap, and see them all side by side on My businesses. If an accountant keeps your books, they see every client business from their own firm dashboard.

It depends on the billing cycle. Monthly plans start with a 14-day free trial — we ask for a card upfront and it converts to your chosen plan automatically after 14 days unless you cancel. Annual plans (including the Founding Members deal) are billed up front and come with a 30-day money-back guarantee instead — if it isn't for you, ask for a full refund within 30 days. Either way, cancel anytime.

Founding Members lock in 50% off the first year — Co-Pilot is $114 and Command is $210 for year one. When your annual plan renews, it moves to the standard annual price — $182 Co-Pilot, $336 Command — which is still 20% off paying monthly. (Auto-Pilot isn't part of the founder offer; it's $86/yr standard.) We'll email you before any renewal, and you can cancel anytime.

Yes. Cancel anytime from your settings — no support ticket, no retention call. Monthly plans start with a 14-day free trial, and annual plans come with a 30-day money-back guarantee, so either way you can try Core Books AI risk-free.

Yes. Core Books AI was formerly Cash Basis AI: the same company, the same product and the same login. Your books, bank connections and plan carried over unchanged, so there is nothing to move or set up again.

Cash basis records income and expenses when money actually moves — when a customer pays you or you pay a bill. Accrual records them when they are earned or incurred, regardless of when cash changes hands. The difference is entirely about timing.

Most freelancers, sole proprietors, and small service businesses are better off on cash basis: it is simpler, mirrors your bank account, and is allowed for the IRS by businesses under the gross-receipts threshold (about $32 million). Accrual makes sense mainly for businesses with inventory, that need GAAP financials for lenders or investors, or that want precise month-to-month profitability.

Yes. Businesses with average annual gross receipts under roughly $32 million (inflation-adjusted) can generally use the cash method for federal income tax. Most self-employed people fall well under that limit.

Yes, though changing your accounting method for tax purposes usually requires filing IRS Form 3115. Many businesses start on cash basis for simplicity and only move to accrual if they grow into a situation that requires it.

For many self-employed people, 30% covers self-employment tax plus federal and state income tax. But it can fall short if you earn a lot, live in a high-tax state, or have significant other income — those situations can push you toward 35–40%. Run your actual numbers to be sure.

On net income — your revenue minus legitimate business expenses. Deductions lower the income you owe tax on, so tracking them well directly reduces how much you need to save.

A separate high-yield savings account works well. Moving your tax percentage out of your checking account the moment you get paid keeps you from accidentally spending it, and it earns a little interest until the quarterly due date.

The 2026 federal estimated tax due dates are April 15, 2026 (Q1), June 15, 2026 (Q2), September 15, 2026 (Q3), and January 15, 2027 (Q4). If a date falls on a weekend or federal holiday, it moves to the next business day.

You avoid an underpayment penalty if you pay at least 90% of your current-year tax, or 100% of last year’s total tax (110% if your prior-year AGI was over $150,000) — whichever is smaller. Paying to the prior-year number is the easiest way to stay penalty-proof even if this year turns out bigger than expected.

The IRS charges an underpayment penalty, calculated like interest on the amount you were short, for the time it stayed unpaid. It is not catastrophic for a single missed quarter, but it compounds — and paying late in the year does not fully undo a shortfall from an earlier quarter.

Maybe not. If your W-2 withholding already covers your total tax (including the tax on your side income), you may not owe estimated payments. You can also increase your W-2 withholding to cover 1099 income instead of making separate quarterly payments.

Self-employment tax is 15.3% of your net self-employment earnings: 12.4% for Social Security (up to the annual wage base) and 2.9% for Medicare. It applies to 92.35% of your net profit, and half of it is deductible against your income tax. This calculator computes it automatically alongside your federal income tax.

A common rule of thumb is 25–30% of your net self-employment income, covering both self-employment tax and income tax. High earners or people in high-tax states may need 35–40%. Use the calculator with your real numbers instead of guessing, then read our guide on how much to set aside.

If you expect to owe $1,000 or more when you file, the IRS generally expects you to make quarterly estimated payments (Form 1040-ES). The 2026 due dates are April 15, June 15, September 15, and January 15, 2027. This tool splits your estimated balance into four quarterly payments.

It runs the exact same tax engine as the Core Books AI product: official IRS 2026 federal brackets, standard deductions and Social Security wage base, plus self-employment tax, the 0.9% Additional Medicare tax and the 20% qualified business income (§199A) deduction. State tax uses a simplified effective-rate model for planning, so your actual state liability may vary. Treat the result as a planning estimate, not tax advice.

Yes. Enter your W-2 wages and your 1099/self-employment income separately. The calculator correctly accounts for Social Security wages already covered by your W-2 job so you're not double-taxed past the wage base.