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Many transient and variable sources detected at multiple wavelengths are alsoobserved to vary at radio frequencies. However, these samples are typicallybiased towards sources that are initially detected in wide-field optical, X-rayor gamma-ray surveys. Many sources that are insufficiently bright at higherfrequencies are therefore missed, leading to potential gaps in our knowledge ofthese sources and missing populations that are not detectable in optical,X-rays or gamma-rays. Taking advantage of new state-of-the-art radio facilitiesthat provide high quality wide-field images with fast survey speeds, we can nowconduct unbiased surveys for transient and variable sources at radiofrequencies. In this paper, we present an unbiased survey using observationsobtained by MeerKAT, a mid-frequency ($\sim$1.4 GHz) radio array in SouthAfrica's Karoo Desert. The observations used were obtained as part of a weeklymonitoring campaign for X-ray binaries (XRBs) and we focus on the field of MAXIJ1820+070. We develop methods to optimally filter transient and variablecandidates that can be directly applied to other datasets. In addition to MAXIJ1820+070, we identify four likely active galactic nuclei, one source thatcould be a Galactic source (pulsar or quiescent X-ray binary) or an AGN, andone variable pulsar. No transient sources, defined as being undetected in deepimages, were identified leading to a transient surface density of$<3.7\times10^{-2}$ deg$^{-2}$ at a sensitivity of 1 mJy on timescales of oneweek at 1.4 GHz.

Search and identification of transient and variable radio sources using MeerKAT observations: a case study on the MAXI J1820+070 field