Why your Amazon delivery postcode changes the price you see

Why does your Amazon delivery postcode change the price?

Your Amazon delivery postcode changes the price you see because Amazon works out the offer it shows for a specific delivery address. The "Deliver to" line at the top of the page, or in the buy box, tells you which address that is. Change it, and Amazon may show a different seller, a different delivery charge, a different date, or say the item cannot be delivered at all. In the US the same applies to your ZIP code.

For anyone tracking Amazon prices to set eBay prices, this is not a curiosity. If your readings are taken at different addresses, you are comparing different offers and calling it a price change. Your repricer then reacts to noise: raising prices one day, lowering them the next, while the real cost has not moved at all. Fixing the address is one of the cheapest improvements you can make to the quality of your price data.

What changes when the delivery address changes?

Several parts of the buy box depend on where the item is going.

The item price of a given seller's offer may well be the same everywhere. The price you see in the buy box changes because the buy box itself can hold a different offer.

Which areas tend to show different offers?

Amazon does not publish a map of this, but some patterns are easy to check for yourself by changing the postcode on a product page.

• Remote and island areas. In the UK, addresses in the Scottish Highlands and islands, Northern Ireland, the Isle of Man and the Channel Islands can see delivery charges, slower dates or restrictions that the mainland does not.
• Addresses abroad. A delivery address in another country changes the whole page: the offers, the delivery charges and often the currency.
• Areas far from stock. Delivery dates can be a day or more later in areas further from where the stock is held.
• US states. Sales tax is calculated by delivery address at checkout on Amazon.com, so the final cost differs by state even when the listed price does not.

Try it with a few of your own products. Read the page at your usual postcode, then at a remote one, and note what changes.

How should you choose a postcode for price tracking?

The aim is a postcode that gives readings you can rely on and compare from day to day.

1. Use a real, realistic address. Pick a postcode that reflects where you actually need items delivered.
2. Prefer the mainland. A mainland postcode avoids island and remote surcharges that would make your costs look higher than normal.
3. Keep it fixed. Use the same postcode for every reading of every product.
4. Write it down. Record the postcode with your readings so you can spot one taken elsewhere.
5. Match your marketplace. For Amazon.co.uk, use a UK postcode; for Amazon.com, a US ZIP code. A mismatch can show foreign offers and currencies.

If your own eBay listings offer postage to remote areas, remember that your costs there may be higher. Many sellers set their postage policies to cover the mainland only, or charge extra for remote areas, for exactly this reason.

What goes wrong when readings use the wrong address?

A reading at the wrong address can look perfectly normal and still be wrong. The usual mistakes are these.

• Foreign currency read as local. A page shown for an address abroad can quote prices in another currency. Read as pounds, a dollar figure produces a nonsense eBay price.
• A remote surcharge counted as your cost. Your prices rise for no real reason, and your listings stop selling.
• A different seller treated as a price change. Your history fills with false changes that are really address changes.
• "Cannot deliver" treated as out of stock. Your listing goes to zero even though the item is available at your real address.

A hypothetical example

Example: suppose you track a pair of headphones at your usual mainland postcode, where the buy box shows £39.99 with free delivery, arriving tomorrow. One day the browser's delivery location changes to an island postcode. The buy box now shows a different seller at £39.99 plus £6.99 delivery, arriving in four to six days. A tracker that does not check the address sees your cost rise to £46.98 and pushes your eBay price up by about £8 with a typical markup. Your listing stops selling for no real reason until the next correct reading puts it back. Had the tracker read a cheaper offer at the wrong address instead, the error would have run the other way and sold items below cost.

How do you check the address before trusting a reading?

The fix is simple: never trust a price without the address it was read at.

• Look at the "Deliver to" line on every page you read, by hand or by software.
• Reject or hold any reading where the postcode or country is not the one you chose.
• Check the currency symbol on every reading against your marketplace.
• Be wary of readings taken while travelling or on a different connection, which can change Amazon's guess of your location when you are signed out.

Dropizon's extension reads the live buy box in a real browser tab on your own computer, at a delivery postcode you choose, and a currency guard checks every push. The Amazon price tracker for eBay page explains the reading process, and the Amazon buy box guide covers what the rest of the panel tells you.

Signed in or signed out

When you are signed in, Amazon uses the default address on your account unless you pick another on the page. When you are signed out, it estimates a location, often from your internet connection, and that estimate can be wrong or can change from one day to the next. A tracker reading pages while signed out may therefore drift between locations without you noticing.

The safest habit is to set the delivery location explicitly and check it on every reading. If you use more than one computer or browser profile, make sure each one is set to the same postcode, or your readings will disagree with each other for no visible reason.

Why the date matters as much as the price

A postcode further from Amazon's stock can show a later delivery date even when the price is identical. If you set your eBay handling time from readings at a well-served postcode, buyers in slower areas may receive items later than your listing promised. Check a few products at a slower postcode and make sure your handling time allows for the difference.

What does eBay expect whichever postcode you use?

The postcode you read at is about accurate costs. It does not change your responsibilities on eBay. eBay allows dropshipping from a wholesale supplier, but listing an item and then buying it from another retailer or marketplace that ships directly to your buyer is not allowed under eBay's drop shipping policy.

The same policy makes you responsible for delivery within the time frame on your listing and for your buyer's satisfaction. If your buyers are spread around the country, your delivery promise has to hold for all of them, not just for the postcode you track at.

A postcode checklist

• Choose one realistic mainland postcode, or one US ZIP code, for all readings.
• Make sure the postcode matches the Amazon marketplace you read, on every computer you use.
• Check the "Deliver to" line and currency before trusting a price.
• Hold readings taken at any other address, and re-read them at the right one.
• Set your eBay postage policy to match the areas you can deliver to at your costs.
• Re-test a few products at a remote postcode now and then, so you know how different it is.
• Check your sourcing model against eBay's drop shipping policy.