If you haven't yet connected UPS to SKULabs, follow How to connect your UPS account to SKULabs first.
Step 1: Turn on Negotiated Rates in SKULabs
Go to Settings > Shipping > Carrier accounts and edit your UPS account.
Make sure Negotiated Rates is checked, then save. It is checked by default on new UPS accounts.
Step 2: Verify your account with UPS
UPS only returns negotiated rates when the UPS.com login you used to authorize SKULabs has your shipper account number added and verified with a recent invoice. To add it:
Find a recent UPS invoice. It must be one of your last 3 invoices and not older than 90 days. In the UPS Billing Center, open the Invoices tab.
On UPS.com, log in with the same user you used to connect SKULabs, click your profile name, and open Payment Options.
Choose Add Existing Account, enter the account number, name, and postal code, and click Next.
Enter the invoice details from the first page of the invoice (not the summary): invoice number with all leading zeros, invoice date exactly as shown, invoice amount without the $ sign, and the Control ID (case sensitive). Click Submit.
It may take UPS 24 to 48 hours to start returning negotiated rates.
Still seeing published rates instead of negotiated rates?
If UPS does not return a negotiated rate, SKULabs shows the standard published rate instead.
Errors such as "Shipper Number is not qualified to receive negotiated rates" or "Account authentication is required to be completed to get negotiated rates" mean step 2 is not finished, or you authorized SKULabs with a different UPS.com user. Complete step 2 for that user, or reconnect UPS with the user that has the verified account.
If the account is verified and you still get published rates, contact your UPS representative to confirm your negotiated rates are active for API use.