Acid-free: A pH (acidity test) reading of 7.0 (neutral) or higher (alkaline) in a substance is a requirement for archival housing and storage materials, as acids can weaken cellulose in paper, cloth and board. Acids also weaken proteinaceous material.

Acceptable risk: A risk whose frequency and extent cannot cause a major loss to the organisation (e.g. damage of an object that forms part of a collection, health damage etc.). The level of acceptability, i.e. the extent of acceptable loss, is defined by the organisation itself on the basis of moral criteria and the laws and regulations of the country.

Access: (in the context of Collections Management, Security etc.): The process of controlling who enters or leaves a secure collections storage or study area, when they may enter and leave, and where they may go and what they may do after they are inside.

Access: (in the context of Visitor Services, Marketing etc.): Giving the general visitor or specialist the opportunity to use the displays, facilities and services of the museum, its research and study collections, and to meet staff: This also includes access at the appropriate intellectual level, and which is free from social and cultural prejudice.

Account: Individual record established for each category of asset, liability, fund balance, expense, or revenue.

Account payable: Debt or obligation due to suppliers or vendors for goods purchased or services rendered.

Account receivable: Money due to the organization from services rendered, donations or dues promised, grants awarded, loans made, or employee advances (not yet accounted for) due but not yet paid.

Acquisitions: Additions to the museum's collection, whether by donation, bequest, purchase, field collecting or exchange.

Advisory board (or committee): (a) Group of leaders with specific expertise responsible for providing counsel and advice to public service organizations. (b) Group of individuals, usually well known, influential, or prominent, whose public support and endorsement supplies credibility.

Advocacy: Investment in creating long-term relationships with the museum's current and potential future public. Having a loyal group of visitors and supporting local community can provide persuasive evidence to politicians, businesses and the press that the museum is a successful organisation and worth investing in.

Annual report: Yearly report, usually focused on financial or organizational conditions, compiled and published by the organization's leadership.

Appraisal (collections management): The authentication and valuation of an object or specimen. In certain countries the term is used for an independent assessment of a proposed gift for tax benefit purposes.

Appraisal (personnel management): The periodic review, usually annual, of an individual employee by a senior representative of the employer, which examines past performance and future responsibilities, and training and other needs.

Audit: (a) Process to examine the records, files, and accounting documents of an organization, to ensure compliance with internal revenue codes. (b) Examination of financial records in accordance with procedures designed to ascertain the validity and accuracy of the financials.