The two main bookkeeping methods are cash basis and accrual basis. Both are legitimate, and the IRS allows most small businesses to choose either one. The right choice depends on how your business operates and what kind of financial picture you need to see.

Cash basis records income when money hits your account and expenses when money leaves. If you invoice a customer in December but they pay in January, that revenue shows up in January. Simple. Intuitive. Matches your bank statement.

Accrual basis records income when you earn it and expenses when you incur them, regardless of when cash moves. That December invoice counts as December revenue even if payment comes later. Materials you bought on credit in November hit November’s books even if you pay the bill in December.

For service businesses with straightforward operations and minimal receivables, cash basis often works fine. You get paid quickly, you pay your bills promptly, and cash flow and profitability look roughly the same. A consultant who bills and collects within the same month might not gain much from accrual accounting.

Accrual becomes more valuable when timing gaps exist between work and payment. Contractors billing progress payments on longer projects need accrual to see which jobs are actually profitable. Businesses that buy materials on credit need accrual to match those costs against the revenue they generate. If you’re invoicing $30,000 in December but not collecting until February, cash basis makes December look terrible and February look artificially good.

The IRS requires accrual basis for businesses with inventory if revenue exceeds $26 million. Below that threshold, you have flexibility. Massachusetts follows federal rules, so no additional state requirements apply.

Single-entry versus double-entry is a separate question, but modern accounting software makes it mostly irrelevant. QuickBooks and similar programs use double-entry accounting behind the scenes. You don’t need to understand debits and credits to categorize transactions correctly. The software handles the journal entries. Your job is accurate categorization and consistent recording.

Whatever method you choose, consistency matters more than perfection. Full-service bookkeeping with monthly closes and reconciled accounts gives you reliable numbers. Switching methods mid-year or ignoring the books for months creates problems no method can fix.

If you’re unsure which approach fits your situation, ask your accountant. They’ll recommend a method that works for tax purposes and provides the financial visibility you need. Most growing businesses eventually shift to accrual because it shows a more accurate picture of performance, especially when timing differences between work completed and cash collected start adding up.

The best business bookkeeping method is ultimately the one you maintain consistently and that matches how your business actually operates. A simple system updated weekly beats a sophisticated system ignored for months.