I have two zone rates set up;
Royal Mail Standard Delivery
Enable Zones Method
True
Calculation Method
Weight
Tax Class
--none--
Tax Basis
Shipping
Sort Order
20
Skip Countries, use a comma separated list of the two character ISO country codes
Zone 1 Countries
GB
Zone 1 Shipping Table
100:0.95,250:1.75,500:2.50,750:3.25,1000:3.75,2000:5.00,4000:8.00,6000:10.50,10000:14.00,1000000000:999.99
Zone 1 Handling Fee
0
Handling Per Order or Per Box Zone 1 (when by weight)
Order
Zone 2 Countries
Zone 2 Shipping Table
Zone 2 Handling Fee
0
Handling Per Order or Per Box Zone 2 (when by weight)
Order
Zone 3 Countries
Zone 3 Shipping Table
Zone 3 Handling Fee
0
Handling Per Order or Per Box Zone 3 (when by weight)
Order
Courier
Enable Zones Method
True
Calculation Method
Weight
Tax Class
--none--
Tax Basis
Shipping
Sort Order
30
Skip Countries, use a comma separated list of the two character ISO country codes
Zone 1 Countries
GB
Zone 1 Shipping Table
1000:3.50,2000:4.50,5000:6.50,999999:7.50
Zone 1 Handling Fee
0
Handling Per Order or Per Box Zone 1 (when by weight)
Order
Zone 2 Countries
Zone 2 Shipping Table
Zone 2 Handling Fee
0
Handling Per Order or Per Box Zone 2 (when by weight)
Order
Zone 3 Countries
Zone 3 Shipping Table
Zone 3 Handling Fee
0
Handling Per Order or Per Box Zone 3 (when by weight)
Order
If the customer selects the second (courier) option, it reverts to Royal Mail on the next page.