This is because providers are allowed to increase prices mid-contract, usually by the rate of inflation plus a fixed amount, of around 4%, on top.

Price rises are linked to either the consumer price index (CPI) or the retail price index (RPI) for December, which are both at 40-year highs of 10.5% and 13.4% respectively.

Not all providers apply mid-contract hikes and those that don’t allow customers to leave if the price increases.

But for those that have mid-contract price hikes written into the terms and conditions, customers usually only have the option of paying the higher fee until the contract has ended.

Planned price hikes

BT, Plusnet and EE are all planning to push up prices by 14.4% in April which is the rate of CPI inflation plus 3.9%.

For a customer paying £10 per month, the hike of 14.4% would push their monthly cost up £1.44 to £17.28. While a monthly bill of £50 would rise £7.20 to £86.40, according to research from Uswitch.  

Below are all of the planned mid-contract price rises for broadband customers as compiled by the comparison website:

• BT: 14.4% (CPI + 3.9%)
• Community Fibre: up to 13.4% (it may hike prices by CPI + a maximum of 2.9%)
• EE: 14.4% (CPI + 3.9%)
• Plusnet: 14.4% (CPI + 3.9%)
• Shell Energy Broadband: 13.5% (CPI + 3%)
• Talktalk: 14.2% (CPI + 3.7%)
• Vodafone: 14.4% (CPI + 3.9%)

John Lewis Broadband, Hyperoptic and Virgin Media are not planning a mid-contract price rise while Sky and Now said “services are variable and our prices and services can change”. However, they can introduce price rises at other points.

Price rises for mobile phone customers

The following price hikes are planned for pay-monthly mobile customers from April:

• BT Mobile: 14.4% (CPI + 3.9%)
• EE: 14.4% (CPI + 3.9%)
• iD Mobile: 13.4% (RPI)
• O2: 17.3% (RPI + 3.9%)
• Talkmobile: 14.4% (CPI + 3.9%)
• Three: 14.4% (CPI + 3.9% for new and upgrading customers, 4.5% for existing customers)
• Virgin Mobile: 17.3% (RPI + 3.9%)
• Vodafone: 14.4% (CPI + 3.9%)

Giffgaff, Lebara, Tesco Mobile and VOXI have no planned price rises while Sky Mobile states in its terms and conditions “we may change the price”.

Some providers, such as Virgin Mobile and O2 only apply price hikes to the ‘airtime’ portion of a contract. This is the calls, data, and minutes and not the amount paid for a handset.

Customers ‘cannot predict the scale of price rises’ when they sign up

Consumer groups have urged telecoms providers to rethink price hikes in light of surging inflation and the cost of living crisis.

Ernest Doku, telecoms expert at Uswitch.com, said: “If you are worried about how these price rises affect you, review the terms and conditions of your contract or double-check with your provider to see what might be in store.

“Consumers cannot predict the scale of these rises when they sign up for a deal, which places all of the risk onto the customer. We firmly believe providers who impose inflationary increases should allow them to leave their contract early without penalty, or offer contracts where the price remains fixed for the duration.”

Rocio Concha, Which? director of policy and advocacy, said: “With households up and down the country struggling to make ends meet, many people will be worried that the cost of everyday essentials continue increasing.

“Which? is calling on providers to carefully consider what level of price rises are justified and empower their customers, by letting them leave without penalty if they face mid-contract price hikes. It is completely unfair that people are trapped in this situation and telecoms providers must play their part to support their customers through the cost-of-living crisis.”

If your bill is rising, vote with your feet

Even if you are still locked into a contract, you could save money by switching. If you’re in the last six months of a fixed contract you could be required to pay a penalty fee to leave – but this may be less than the amount you would pay if you remained with your current provider.  

Broadband customers on average can save £162 a year by switching their provider, while customers on pay-monthly mobile deals can save an average of £321 annually by moving their handset over to a SIM Only contract, according to Uswitch.