Hampshire have signed Afghanistan spinner Mujeeb Ur Rahman and New Zealand batsman Colin Munro for the Vitality Blast.
Carlos Brathwaite has signed to play in Kent Spitfires' opening four matches of the 2018 Vitality Blast.
Derbyshire have announced the signing of experienced Pakistan fast bowler Wahab Riaz for the Vitality Blast this summer.
Glamorgan have signed Australia's Usman Khawaja as their second overseas player for this summer's Vitality Blast.
Middlesex have announced the signing of Australian all-rounder Ashton Agar for this year's Vitality Blast.
Yorkshire have signed Australia seamer Billy Stanlake for a minimum of 12 games in their 2018 Vitality Blast campaign.
A look back at all the news, reports and action from the 2017 NatWest T20 Blast.
Australia leg-spinner Adam Zampa has been signed by Essex for the whole of their 2018 T20 Blast campaign.
Sussex have secured the signing of Afghanistan leg-spinner Rashid Khan for the first half of the 2018 T20 Blast.
Australia all-rounder James Faulkner will return to Lancashire after signing a two-year T20 contract with the county.
The 2018 T20 Blast will begin with a repeat of the 2017 final between Nottinghamshire Outlaws and Birmingham Bears.
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