you need to look at the rules in the Town and Country Planning (General Permitted Development) Order. It depends on various factors such as position in relation to the existing house and road, how near to the house, whether in a Conservation Area or AONB etc etc. All local authorities would adhere to the GPDO – although if no one complains about it then they may not do anything.
Is it for business use? As noted, there is some risk of a change of use permission being needed unless the use can be considered ancillary to the use of the dwelling as such.
On balance you’re probably OK but I’d check it out before laying out cash.
Is it a shortened container? I thought the smallest was 20ft long?