Sage API Integration Cost: What to Expect in the UK

A custom Sage Accounting integration costs from £850 for a one-way order sync, which sends orders, customers and VAT into Sage, and from £1,495 for a full sync that adds products, stock and payment reconciliation. Bigger builds, such as several stores into one Sage business or a two-way sync, are quoted from your spec. The price is the development work; your Sage subscription is paid to Sage separately.

This guide covers what you get at each level, what pushes the price up or down, and what it costs to run afterwards. It applies to Sage Accounting, Sage's cloud software. Sage 50, the desktop software, connects differently, so it's quoted separately.

Three build tiers

Order sync: from £850

Orders, customers and VAT sent from your shop into Sage, one way. Each order becomes a sales invoice, each customer becomes a contact (or is matched to the existing one, so you don't get duplicates), and VAT is mapped to your Sage tax rates. You approve the connection from your own Sage login, it's tested on a Sage trial account first, and failed syncs are logged and flagged rather than quietly skipped. For shops whose main job is getting orders into Sage without anyone typing them in.

Full sync: from £1,495

Everything in the order sync, plus your shop's products matched to products in Sage, stock levels kept in step, and payments recorded against their invoices so invoices show as paid and the bank reconciliation lines up. Requests are queued and retried within Sage's limits, and every sync is logged. For shops where reconciling payments by hand, or keeping stock figures in two places, is the real pain.

Multi-store and custom: quoted

Several stores into one Sage business, a two-way sync where information also flows from Sage back to the shop, or custom rules for your products and VAT. These are quoted from a short written spec, because the work depends on how your stores and your Sage business are set up.

What drives the cost up

More types of data. Orders and customers are the starting point. Each extra type, such as products, stock, payments or refunds, has its own rules for matching and its own ways of going wrong, so each one adds design and testing time.

Two-way sync. Sending data one way, from the shop into Sage, is the simplest arrangement. A two-way sync, for example stock levels managed in Sage and sent back to the shop, needs rules for which system wins for each piece of information, so the two never overwrite each other.

VAT and product matching. In version 3.1 of the Sage Accounting API, each invoice line has to carry its VAT amount, unless it's zero-rated, exempt or no-VAT. The integration has to send figures that match your shop's exactly, or totals drift by a penny here and there. Mixed VAT rates, products that don't match one-to-one with Sage, and bundles or variations all add time.

More than one store. Each extra store needs its own connection, its own mapping and its own testing, and the rules for keeping the stores' customers and products apart in one Sage business have to be agreed.

Importing historic orders. Sending only new orders is straightforward. Bringing months or years of past orders into Sage means a bulk import that has to be run in batches, checked against what's already in Sage so nothing is entered twice, and agreed with your accountant first.

Error handling and retries. Sage limits how many requests an integration can make, and when the limit is reached it turns requests away with an HTTP 429 error. A well-built sync queues its requests and tries again after a pause, so a busy sale day delays records rather than losing them. That queueing and retrying is part of every build, but busy shops need more of it.

Testing without a sandbox. Sage doesn't provide a sandbox for the Sage Accounting API, so the integration is built and tested on a separate 30-day trial business, set up with your tax rates and ledger accounts. Setting that up to match your real business is part of the work.

What drives the cost down

One store, one Sage business. No mapping between several shops and one set of books.

Standard VAT. Products that are all standard-rated, or all zero-rated, make the VAT mapping simple.

Products that already match. If your shop's product codes already match the products in Sage, there's little matching to build.

Only new orders. Starting from a set date, with past orders left as they are, avoids a bulk import.

Ongoing costs

Your Sage subscription, paid to Sage. The integration doesn't replace it.

Hosting. A sync built into your website runs on your existing hosting. If an integration needs its own small server, the quote says so and what it costs to run.

Support. An optional support retainer, from £49 a month, covers monitoring, fixes when Sage changes something, and small changes as your business changes. It isn't required, and there's no long contract.

Connector apps and automation tools

Off-the-shelf connector apps and automation tools such as Zapier can send shop orders into Sage Accounting. For one shop with simple VAT that just wants orders in Sage, they're often cheaper than a custom build, and I'll say so if one fits. When you compare, look at the ongoing fee over two or three years, what happens when a sync fails, and whether it handles payments, refunds and your VAT rates the way your accountant wants.

A custom sync is worth it when your rules don't fit what the connector does: several stores, mixed VAT, products that don't match one-to-one, stock managed in Sage, or payments that need reconciling properly. For WooCommerce specifically, see WooCommerce and Sage integration.

For the full service details, see Sage Accounting integration. Using Xero instead? See what a Xero integration costs.