Won deals in Salesforce, correct invoices in Xero

Zestcode Automation builds bespoke Salesforce to Xero integrations that turn won opportunities and orders into Xero invoices, after checking the contact, line prices, VAT and references, with a person approving each one by default. Where an ERP or inventory system sits between the two, the order goes there first and Xero is invoiced the way it already is.

Why a won deal and its invoice drift apart

Finance teams in sales-led businesses describe the same handful of problems. An opportunity is marked won with a discount that never reaches the invoice. The account name in Salesforce doesn’t match the contact in Xero, so a second contact gets created. A deal closes in March, the goods ship in April and the invoice date follows the wrong one. The customer’s PO number, which their accounts payable team insists on, is missing from the reference, and payment sits on hold until someone reissues the invoice.

Each one is quick to put right on its own, but only if someone notices before the invoice goes out, rather than when the customer queries it a month later.

The checks before anything reaches Xero

Each won deal or order runs through a list of checks, written as ordinary code so the results are predictable:

1. Contact. Is there a Xero contact for this Salesforce account? If more than one is a plausible match, the reviewer chooses.
2. Lines and prices. Do the products, quantities and agreed prices from the opportunity or quote add up to the deal value?
3. VAT. Does each line carry the right tax treatment for the customer, such as zero-rating for qualifying exports?
4. Reference. Is the customer’s PO number present? If they emailed one, AI reads it from the email and its attachments and attaches it to the deal.
5. Duplicates. Has an invoice already been raised for this opportunity or PO?
6. Account codes and tracking. Does each line map to the sales account and any tracking categories your finance team uses in Xero?

Anything that fails appears as a warning in the review queue. Nothing is created in Xero until someone approves it, unless you later decide certain clean deals can go through on their own. Every approval and edit is kept in an audit log, which is handy at year end.

Direct to Xero, or through your ERP first?

The right route depends on what sits between sales and accounts.

In the second and third cases, the platform never writes to Xero itself. Your inventory system keeps its existing Xero connection, which avoids the classic mistake of two systems both raising an invoice for the same sale. The ERP integration page explains how orders reach a system of record.

What about off-the-shelf sync apps?

There are apps that sync Salesforce and Xero, and if your deals translate neatly into invoices, one of them may be the cheaper answer. They tend to run short on the checks: approval before posting, PO numbers taken from emails, discounts compared against what was actually sold, and billing rules specific to your business. A bespoke platform suits companies where those details create real work every month.

What you own, and what you pay

The finished platform is yours: your hosting account, your code, and no fee per Salesforce or Xero user. Support after launch is available on a monthly plan from £80 if you want it, but nothing obliges you to take it.

Most Salesforce to Xero builds fall within the £8k–£12k ex VAT range we quote for order automation and take around six weeks. Running costs come to a hosting bill of about $25 a month, plus a few pence per order when AI is reading emailed POs. A free specification comes first, followed by a fixed quote that holds for 90 days. Book a discovery call through the contact page.