Halifax Legal Solutions will provide customers with access to legal advice as well as products such as wills and tenancy agreements for an £89 annual membership fee.
The service will initially be promoted by direct work, but Halifax owner HBOS is also considering advertising and digital activity.
Membership gives customers unlimited access to the services online or via a telephone service manned by a team of qualified professionals, including solicitors and barristers.
Customers will be able to draft legal documents, including powers of attorney and letters of complaint about faulty goods, via the Legal Solutions website.
The launch follows the successful introduction last year of Halifax Conveyancing, a panel of legal firms offering a conveyancing service for home buyers. 'The natural next step was to move into everyday legal products,' said a spokesman for the bank.
Although some retailers, including WH Smith, offer do-it-yourself legal kits, such as divorce or will writing, HBOS believes there is a gap in the market.
It launched the conveyancing service after mortgage customers asked it to recommend legal professionals.
The UK legal services market is worth about £8bn, according to the Government Department for Constitutional Affairs.
Halifax has been able to get ahead of the government's imminent passing of a Legal Services Bill, which will allow firms outside the legal profession to offer legal services, because of the ties it forged for its conveyancing service.
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