This list of Mozart symphonies of spurious or doubtful authenticity contains 39 symphonic works whose initial attribution to Wolfgang Amadeus Mozart has subsequently been proved spurious, or is the subject of continuing doubt. The number of symphonies actually written by Mozart is imprecisely known; of the 41 formally numbered, three (Nos. 2, 3 and 37) are established as by other composers and another, No. 11 (K. 84/73q), is considered by scholars to be of uncertain authenticity. Outside the accepted sequence 1–41, however, there are around twenty other genuine Mozart symphonies,[1] and beyond these, a larger number of problematic works which have not been authenticated as Mozart's. Some of these may be genuine; dubious works are often treated as authentic by the compilers of collected editions—eight (K. 76/42a in F major, K. Anh. 214/45b in B♭ major, K. 81/73l in D major, K. 97/73m in D major, K. 95/73n in D major, K. 84/73q in D major, K. 75 in F major, and K. 96/111b in C major) are in the main body of the 1991 Neue Mozart-Ausgabe (NMA: English New Mozart Edition), and another two (K. Anh. 220/16a/Anh.C 11.18 in A minor and K. Anh. 216/Anh.C 11.03/74g in B♭ major) are included in the supplementary 2000 volume of works of doubtful authenticity. Some, however, have long been accepted as the works of other composers, who in many instances have been positively identified.
Many of the authentication difficulties arise from early Mozart symphonies, where original autograph scores are missing. In some instances the main body of the work has been entirely lost, its identity being preserved only through an incipit (record of the opening few bars) cataloged by Breitkopf & Härtel, who published the Alte Mozart-Ausgabe (AMA) in 1883. The informal 18th century methods of publishing and distributing musical works caused additional confusion. Cataloging errors based on inadequate information, and an occasional over-eagerness to attribute new discoveries to Mozart has added to the problem. However, the "spurious and doubtful" list of symphonies is not fixed, as new evidence can sometimes lead to authentication; it can also throw doubt upon, or disqualify, symphonies once generally accepted as genuine Mozart.