The most reliable method is opening a separate savings account dedicated solely to taxes and transferring a percentage of your profit into it every month. When the account is separate, you stop seeing that money as available for operations or owner draws. It sits there until you need it for quarterly payments or your year-end bill.

The percentage you set aside depends on your business structure, income level, and state. In New Jersey, between federal income tax, state income tax, and self-employment tax, business owners often need to reserve 25 to 35 percent of net profit. That range is wide because a sole proprietor earning $80,000 faces different rates than an S-corp owner with $150,000 in distributions. Your accountant can give you a specific target based on your actual situation and expected income.

If calculating profit monthly feels like too much work, use gross revenue as a simpler proxy. The percentage will be lower since you’re working from a larger number. Some business owners set aside 10 to 15 percent of revenue as a rough estimate. This approach works when your margins stay consistent, but it’s less precise than using actual profit figures.

Make the transfer automatic or at least habitual. Move money right after you close out each month in your books. The goal is making it happen before you have a chance to spend that money on something else. Bookkeeping services that include monthly reconciliation give you a natural trigger point for making the transfer.

Use that dedicated account to make quarterly estimated tax payments. The IRS expects you to pay taxes throughout the year, not just at filing time. If you owe more than $1,000 when you file, you’ll face penalties for underpayment. Making quarterly payments from your tax savings account keeps you current and avoids those penalties.

Review your set-aside rate quarterly or whenever your income changes significantly. A slow quarter means you set aside less in absolute dollars. A big contract or unusually profitable stretch might mean you need to bump the percentage temporarily. The goal is ending the year with enough in the account to cover your bill, with maybe a small cushion for adjustments.

Building tax reserves into your overall cash flow planning makes this easier to manage. When you know your fixed costs, your variable costs, and your tax obligation each month, you can see what’s actually available for growth or owner distributions. The set-aside amount gets confirmed with your accountant so everyone agrees on the target.

The alternative is getting a surprise bill in April and scrambling to pay it. Some business owners end up taking out loans or putting taxes on credit cards because they didn’t plan ahead. That’s expensive and stressful. Setting aside money monthly takes the surprise away completely.