Sage was formed in Newcastle in 1981, floated on the London Stock Exchange in 1989, and has been in the FTSE 100 since 1999. In its 2025 financial year, revenue grew 10% to £2.5 billion, and more than 2 million businesses use its software.
Its range runs from Sage Sole Trader and Sage Accounting for small businesses, through Sage 50 on the desktop, to Sage Intacct for mid-sized companies. Brightpearl, the retail operations platform, is part of Sage too.
Sage Accounting
Sage Accounting is the cloud product for small businesses, in three plans: Start, Standard and Plus. All three include Sage Payroll and Sage Copilot, its AI assistant, which can help file a VAT return. Plus adds stock and multiple currencies, with unlimited users.
Bank and card feeds bring transactions in automatically, and VAT returns go to HMRC under Making Tax Digital. For sole traders, Sage Sole Trader is ready for MTD for Income Tax.
Accountants use Sage for Accountants free of charge, and around 14,000 of them work with Sage’s products. On Trustpilot, Sage rates 4.0 from more than 20,000 reviews.
Apps and partners
The Sage Marketplace lists more than a hundred apps for Sage Accounting. Sage’s accounting also runs inside other companies’ products, with embedded services supplied to partners such as Tide, Monzo and NatWest.
The API
The Sage Accounting API is REST, free to use, and covers contacts, products and services, sales and purchase invoices, banking, payments, ledger accounts and taxes. The current version is 3.1, which replaced version 3 in July 2026.
Apps connect with OAuth 2.0, with read-only or full access. One sign-in can reach several businesses, which suits accountants and groups. Each app can make up to 1.3 million requests a day.
Integrations keep in step by asking for records created, updated or deleted since their last check, and developers test against a trial account.
Sage and the systems around it
Sage Accounting’s API is free to use and covers sales, purchases and banking, so plenty can flow into it. Online orders can post as daily summaries per channel, supplier invoices can arrive as purchase invoices ready to approve, and payments can be matched to the invoices they settle without a person in between.
Accountants working in Sage for Accountants see the same figures, so cleaner postings save time on both sides. Whichever pieces get connected first, sizing the job comes before the build.