Question to the Home Office:

To ask the Secretary of State for the Home Department, how many online frauds have (a) been reported to the police and (b) resulted in a police investigation in each of the last five years; and how many of those cases so reported have resulted (i) in a suspect being charged and (ii) in a conviction being made in each of the last five years.

The Home Office collects quarterly data on the number of reports of fraud made to Action Fraud and that have been recorded as criminal offences by the National Fraud Intelligence Bureau (NFIB).

The most recently available data for the year ending June 2018 have been published by the Office for National Statistics and can be found in Table A5 here:
https://www.ons.gov.uk/peoplepopulationandcommunity/crimeandjustice/datasets/crimeinenglandandwalesappendixtables

The Home Office collects information on the number of fraud offences that the NFIB refer to police forces for investigation and on the outcomes of such offences. Data is published on an annual basis but only available for the last two years.
These data are published in Table 5.1 and Table 5.2 respectively here:
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/729127/crime-outcomes-hosb1018.pdf

The Home Office does not hold information on the number of convictions for fraud offences as this is the responsibility of the Ministry of Justice.