Note 26 Construction contracts

Worked-up not invoiced income

Group, MSEK 2021 2020
Koncernen, Mkr 2021 2020
Worked-up income on incomplete contracts Upparbetade intäkter på ej avslutade entreprenader 39,416 38,025
Invoiced sales on incomplete contracts Fakturering på ej avslutade entreprenader -37,838 -35,987
Total Summa 1,578 2,038

Invoiced income not worked-up

Group, MSEK 2021 2020
Koncernen, Mkr 2021 2020
Invoiced sales on incomplete contracts Fakturering på ej avslutade entreprenader 53,717 55,948
Worked-up income on incomplete contracts Upparbetade intäkter på ej avslutade entreprenader -49,361 -51,994
Total Summa 4,356 3,954

Change in contract balances

2021 2020
Group, MSEK Worked-up not invoiced income Invoiced income not worked-up Worked-up not invoiced income Invoiced income not worked-up
2021 2020
Koncernen, Mkr Upparbetade men ej fakturerade intäkter Fakturerade men ej upparbetade intäkter Upparbetade men ej fakturerade intäkter Fakturerade men ej upparbetade intäkter
Income recognized in the period included in invoiced income not  worked-up at the beginning of the period Intäkt redovisad i perioden som ingick i fakturerad men ej upparbetad intäkt vid periodens ingång 3,954 4,859
Invoiced during the year, reduced by amounts recognized as income during the year Fakturering under året, reducerad med belopp som redovisats som intäkt under året -4,356 -3,954
Transferred from worked-up not invoiced income at the beginning of the period to accounts receivable Överföring från upparbetad men ej fakturerad intäkt vid periodens början till kundfordringar -2,038 -2,387
Worked-up during the year, reduced by amounts invoiced during the year Upparbetning under året, reducerad med belopp som fakturerats under året 1,578 2,038
Exchange rate differences Valutakursdifferenser 19 -47 -20 -87
Income recognized during the report period from performance obligations met during previous periods was SEK -249 million (-207).

Worked-up income from ongoing contracts is recognized over time. The degree of recognition is calculated on the basis of the project costs incurred at the end of the period in relation to the project costs corresponding to the project income for the whole project.

Contract assignments are recognized in gross on the balance sheet project for projects, either as Worked-up income not invoiced in current assets or as Invoiced income not worked-up in current liabilities. Projects that have higher worked-up income than the amounts invoiced are recognized as assets, while projects that have invoiced more than the income worked-up are recognized as liabilities.