For more details see here: Overpayment Estimator – More Details

Estimator calculations are based on the SIM free device price using GfK market wide sales data for the most common 75% of handsets sold in the UK from the relevant manufacturers’ website (if they sell directly) and major retailers (see below). 

The handset value is taken is the average sales price for the device on its own (SIM free, not as part of a bundled mobile phone contract) across the market, taken from the last week of the month we assume you signed up (based on the how long you’ve told us you’ve been in contract).  We haven’t used the specific amount for your phone each network operator has built into the bundled airtime and handset contract price because that information isn’t available publicly.  Overpayment estimator assumes regular monthly payments over a 24 month contract, which continue without changing after expiry of the 24 month minimum term.  Other network operators offering bundled handset and airtime pay monthly contracts which don’t automatically drop the price to just airtime after 24 months include Vodafone, EE, Three (link to relevant websites) as at as at 17th June 2019.

GfK data includes pricing detail as follows:

Official manufacturer online stores are checked first, e.g. https://www.samsung.com/uk/,  https://www.apple.com/uk/ etc

Then major UK retailers including:

https://www.johnlewis.com

https://www.argos.co.uk/

https://www.carphonewarehouse.com

https://www.tesco.com/phones/shop/sim-free-phones

https://www.amazon.co.uk/

Calculation examples

Out of contract example calculation:

((Phone price - upfront payment) /contract length) x (how long in contract - contract length) = Overpayment estimate

e.g. Phone price payable per month x Months over-paying for phone = total overpayment estimate

e.g. using example phone and value:

Out of contract example calculation:

((Galaxy S6 128GB G920 (£650 - £20 upfront = £630)/24 months) =  26.25 x (35 months - 24 months) 26.25 = £288.75

In contract example calculation: 

((Phone price - upfront payment) /contract length) = Monthly overpayment estimate if still paying after 24 months

Phone price payable per month = Monthly Overpayment estimate after 24 months

(iPhone 6 16GB price £300 - £50 upfront = £250) / 24 months = £10.42

Other network operator plans and terms and conditions.

Note: Pricing and inclusive bundle is not intended to be comparable – length of plan and post minimum term behaviour is the key feature:

EE online sales example and terms and conditions

Vodafone online sales example and terms and conditions

Three online sales example and terms and conditions

O2 online sales example