Spark is blaming a decision from the Commerce Commission, for a rise in home phone and broadband plans.

Its increasing the price of monthly plans by between $2.50 and $4.25 from February.

Spark's Chris Quinn says the company's been offering competitive prices on the expectation that Chorus prices would fall.

But last week's draft decision signalled increases in both wholesale home phone and broadband line charges.

Key price changes

Home phone only - Auckland, Wellington, Christchurch
Current monthly price: $46.00
Cost difference between IPP and FPP Chorus charges: +$5.40
Price change: +$4.00
Price from 1 Feb 2015: $50.00

Home phone only - rest of New Zealand
Current monthly price: $51.00
Cost difference between IPP and FPP Chorus charges: +$5.40
Price change: +$2.50
Price from 1 Feb 2015: $53.50

ADSL Broadband and homephone, entry level 40GB plan
Current monthly price: $75.00
Cost difference between IPP and FPP Chorus charges: +$4.54
Price change: +$4.00
Price from 1 Feb 2015: $79.00

ADSL Broadband and homephone, 80GB plan2
Current monthly price: $85.00
Cost difference between IPP and FPP Chorus charges: +$4.54
Price change: +$4.00
Price from 1 Feb 2015: $89.00

ADSL Broadband and homephone, Unlimited Data plan
Current monthly price: $109.00
Cost difference between IPP and FPP Chorus charges: +$4.54
Price change: -$10.00
Price from 1 Feb 2015: $99.00