Integrations

Connecting Sage Accounting: certified valuations as sales invoices

2 min read · Checked against the product 3 October 2026

Connect Sage Accounting and every certified valuation becomes a sales invoice, with the retention and the VAT treatment set for you, and a payment in Sage marks the valuation paid. For UK organisations on the paid plans.

For UK organisations on Builder, VariationFlow and VariationFlow + QA Flow, and on older paid plans; not on the free plan. An admin or director connects it, and one accounts package can be connected at a time.

What it does

With Sage connected, the certificate you record in VariationFlow becomes the sales invoice in your accounts, and when Sage shows the invoice paid, the valuation follows. An interim application is not a sales invoice, so nothing goes to Sage until the valuation is certified. On Builder, homeowner invoices go across the same way.

• One invoice per valuation: the certified value, and the retention withheld as a minus line on the same VAT rate, so the VAT falls on the net.
• The VAT rate on each line comes from the project’s VAT treatment: 20%, 5%, zero, or the domestic reverse charge.
• Sage numbers the invoice itself. The reference carries the valuation number and the project, or a homeowner invoice’s own number, cut to the 25 characters Sage allows; the full text goes in the notes.
• The invoice carries the billing address held for the customer, which Sage needs, and falls due on the contract’s final date for payment.
• When Sage shows the invoice fully paid, the valuation is marked paid with the date of the payment. Sage sends no notice of a payment, so VariationFlow looks every hour; “Check for payment” looks straight away.

Before you connect

• For a domestic reverse charge job, mark the customer as a reverse charge customer in Sage, with their VAT number. Sage applies the reverse charge to the whole invoice and only for such a customer; VariationFlow says so if Sage refuses.
• Give each customer a billing address in VariationFlow, on the project or the customer record, so the first invoice goes without a stop.

Connect it

1. Go to Settings, Integrations, choose “Connect Sage Accounting”, sign in to Sage and allow access to your business.
2. Under Post sales to, choose the sales ledger account each invoice line posts to. Leave Post retention to as “Same as sales” unless you post retention separately.
3. Tick the box to send each valuation as soon as it is certified, or leave it clear and send each one yourself. Save.

Day to day

• Once a valuation is certified, “Send to Sage Accounting” raises its invoice. Edit the valuation and the same invoice is updated, never a second one. If a send fails, the reason is shown beside it and the retry button sends it again.
• If Sage’s total no longer matches VariationFlow’s figures, the valuation is not marked paid and the reason is shown beside it.
• Disconnecting clears the invoicing settings; set them again after you reconnect.

Common mistakes

• Setting the wrong VAT treatment on the project. The Sage invoice follows it.
• Sending a reverse charge valuation before the customer is marked as a reverse charge customer in Sage.
• Expecting a payment to show at once. Press “Check for payment”, or wait for the hourly look.