What is ERP?

ERP, enterprise resource planning, is software that runs a business's sales, stock, purchases, accounts, people and reports on one shared set of records. Each job is entered once and every module and report reads the same data. For a small business it replaces separate billing, stock, accounting and payroll tools that each keep their own copy of the truth.

ERP: a worked example

On 3 October 2026 Harbour Steel Furniture, a fictional maker of steel furniture, invoices Riverside Stores for 2 Steel rack 4 shelf at $499 each. The value before tax is $998 and tax at 20% is $199.60, so invoice INV-2026-0213 totals $1,197.60. Here is what that one invoice changes.

What does an ERP replace in a small business?

Usually four or five tools that each keep their own copy: a billing app, a stock register or spreadsheet, accounting software such as QuickBooks or Sage, a payroll sheet and a notebook of follow-ups. The work moves into one system, and the month-end job of making those copies agree disappears, because there is only one copy.

When does a small business need an ERP?

When the same sale is typed twice. Typical signs: stock in the books never matches the warehouse, the accountant re-keys invoices into accounting every month, nobody can say what a customer owes without phoning someone, and tax figures are rebuilt from sales and purchase registers before every return. At that point one system costs less than the re-entry.