Previously, a Baptist church building could hold a same-sex blessing service but a Baptist Union minister could not be present, officiate or take part in the ceremony.
However, at the Baptist Union Assembly it was announced that ministers should have 'the freedom to respond to the wishes of their church, where their conscience permits, without breach of disciplinary guidelines'.
Revd Steve Chalke told Premier's Des Busteed that this is an important step forward.
The issue was discussed at the meeting of the Baptist Assembly, which took place over the weekend, with leaders explaining what the recent government changes mean for churches.
Despite the guideline update the Baptist Union's understanding of a Christian marriage remains between "a man and a woman", as the continuing foundation of belief in its Baptist Churches.
And a Baptist minister is required to live and work within the guidelines adopted by the Baptist Union of Great Britain regarding sexuality and the ministry. That includes 'a sexual relationship outside of Christian marriage (as defined between a man and a woman) is deemed conduct unbecoming for a minister'.
Derek Tidball - an ex-President of the Baptist Union and Baptist pastor - gave his reaction to Premier's Victoria Laurence.
The announcement follows a series of conversations held between the BU's Council, Team Leaders and the Baptist Union Steering Group in the wake of the government's introduction of the Same-Sex Marriage Bill last year.
Baptist Union Faith and Society Team Leader Stephen Keyworth spoke to Premier's News Hour about the update.
The Christian Institute which campaigned against the coalition's same-sex marriage bill has strongly condemned the Baptist Union's decision.
Organisation spokesman Calum Webster told Premier's Des Busteed why he doesn't support the BU's decision.
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Meanwhile, the Archbishop of Canterbury has reiterated his opposition to same-sex marriage after being quoted saying it's 'great'.
A spokesperson for Most Revd Justin Welby said he was simply speaking to 'Pink News' about the right of parliament to change the law and his views hadn't changed.
The Anglican leader voted against gay marriage in the House of Lords last year, while the Church of England remains opposed to the law.
The Church of England and the Church in Wales are currently banned from carrying out gay marriage ceremonies under the current legislation, with a vote in parliament the only way of reversing the current status quo.
However, a Church of England priest, Canon Jeremy Pemberton, who is a hospital chaplain in Lincolnshire tied the knot with long-term partner Laurence Cunnington in a ceremony last month.
Canon Pemberton has also reportedly indicated his intension to offer marriage ceremonies to other Anglican same-sex couples.
Up until now Quakers in Britain was the only mainstream Church in England and Wales offering same-sex marriages.