Order provenance

Order data is immutable after purchase. A rate change never alters a placed order — and beyond WooCommerce’s own stored totals, Price Anchor records enough on each line to explain exactly how the price was produced.

What is stamped on the line item

For every anchored order line, Price Anchor records:

• the source currency and source amount — the supplier-currency number you authored;
• the raw market rate at the moment of purchase;
• the actual markup that was applied, including any Pro scoped rule that overrode the global one;
• the effective conversion factor — the single multiplier that turns the source amount into the charged amount, after everything.

These are private accounting fields. They appear in WooCommerce order administration below the relevant line item. They do not appear in customer emails, on the customer’s account pages, or anywhere on the storefront.

Why record the markup separately from the rate

Because “the price was 1,247” is not an answer to “why was the price 1,247”. A month later, with a different global markup and a different rate, the only way to reconstruct a decision is to have both inputs and the resulting factor stored side by side. Storing just the final price is what makes historic pricing disputes unresolvable.

The read path stays clean

Recording this evidence does not put pricing logic on the storefront. The free plugin registers three order-provenance callbacks and Pro registers two cost-provenance callbacks; all are inert outside checkout and order-meta formatting, perform no rate fetch and never calculate a product price. Checkout only copies snapshots that were already locked when the price was written.

Refunds

A refund does not change the stamped evidence — the original line still records what was charged and how. Pro’s Sales report reconciles partial refunds and line discounts on top of that evidence when calculating net product revenue and gross product profit, rather than mutating the original stamps.

Pro: acquisition cost on the order

With Pro, the locked per-unit acquisition amount, its currency, the acquisition-time rate and the resulting unit COGS are stamped on the same order line. A later market-rate update never rewrites that, which is what makes the profit report trustworthy rather than a re-derivation from today’s rate.

Where WooCommerce’s native COGS API exists and is enabled, Pro synchronises only Price Anchor-owned values through it and reads legacy or native order costs through public methods. It never writes WooCommerce’s private meta.