(申請するビザのカテゴリ) >Fiance(e) or proposed civil partner of a British citizen or settled person
(Finacial requirmentで記載されているEvidence requirmens-general informationの抜粋) (1) the requirements in paragraph 1(a)(i)-(iv) are met as if the document were a bank statement; and (2) a building society pass book must clearly show: (i) the account number; (ii) the building society's name and logo; and (iii) the information required on transactions, funds held and time period(s) or as otherwise specified in Appendix FM-SE in relation to bank statements; and/or
(3) a letter must be on the headed stationery of the bank, building society or other financial institution and must clearly show: (i) the account number, (ii) the date of the letter; (iii) the financial institution's name and logo; and (iv) the information required on transactions, funds held and time period(s) or as otherwise specified in Appendix FM-SE in relation to bank statements.
Annex FM Section FM 1.7: Financial Requirement
http://www.ukba.homeoffice.gov.uk/sitecontent/documents/policyandlaw/IDIs/chp8-annex/section-FM-1.7.pdf?view=Binary