Compare Supplier Quotes with AI, Backed by Evidence

What to give the AI for a quote comparison

Give the AI the full text of each quote, not a summary. Price, quantity, lead time, payment terms and scope are often on different pages. An incomplete quote comes back as an incomplete or made-up table.

Add your own request alongside the quotes. State which items you need, in what quantity and by which date. The comparison should follow your request, not the layout each supplier chose.

Write a clear prompt and ask for a source for every row. Tell the AI to write "not in the quote" for anything the offer does not state. This simple rule asks for evidence instead of guesses.

Where possible, provide the quotes in the same format. Use files with selectable text rather than scanned pages. If a page is unreadable, say so clearly, so the AI does not fill that gap with a guess.

Tying every row to evidence in the offer

In a good comparison table, every cell has an address. Which quote, which page, which sentence? A cell without an address is an assumption, not information.

Add an "Evidence" column to the table. Put the relevant sentence from the quote there as a short quotation with its page number. Your procurement manager then sees where each figure comes from at a glance.

The evidence column also speeds up checking. Finding a quotation in the offer takes seconds. If you cannot find it, move that row to your review list.

Watch units and currencies as well. One quote may state prices excluding VAT, another including VAT. The quotation in the evidence column makes this difference visible and prevents a false comparison.

Catching the wrong figure and the missing item

AI can make two kinds of error in quote tables. The first is a wrong figure: unit price, total or lead time gets mixed up. The second is a missing item: a service the quote never mentions appears as "included".

Calculate the totals yourself. Multiply unit price by quantity and compare the result with the table. Even a small gap tells you other cells need checking too.

Use your request list to find missing items. Mark each requested item as present, absent or unclear for every quote. Look closely at items such as installation, transport and after-delivery support.

The example below shows how these errors look in a simple two-quote comparison. The table looks tidy at first glance, yet three cells do not match the quote.

Finishing the table with a checklist

Even when the table looks finished, the last step is the checklist. It makes you run the same checks in the same order, even on a busy day. Quality then depends on the method, not on that day's attention.

Add the list under the table and tick each item. Anyone reading the table sees exactly what was checked. That visibility gives the purchasing decision solid ground.

You do not need to rewrite the list for every comparison. Prepare it once, share it with your team and reuse it in every new round of quotes. Over time, everyone on the team produces tables to the same standard.

Who makes the choice

The AI prepares the table and you check the evidence. Choosing the supplier is a decision for the authorised procurement lead. Do not let the AI add a "recommended supplier" row.

End the table with a clear list of differences: price, lead time and scope. Add open questions for the supplier on a separate line. The decision maker then weighs these differences against their own priorities.

Every role stays clear. The document is prepared quickly, the evidence stays visible and the decision stays with its owner.

Checklist

1. I gave the AI the full text of each quote and my own request list.
2. Every cell in the table has a quotation and page number from the offer.
3. I calculated all totals myself from unit price and quantity.
4. I marked each requested item as present, not stated or unclear for every quote.
5. I wrote "not stated" wherever the quote is silent, and "none" only where it says none.
6. I listed open questions to ask the supplier.
7. There is no "recommended supplier" row; the choice stays with the authorised person.