When a conviction has been vacated as legally invalid, it is important (a) to obtain multiple certified copies of the order vacating the conviction, and important (b) to correct the state and federal criminal history records to reflect the new information that the conviction has been vacated.

First Circuit

POST CON - NUNC PRO TUNC ORDERS
The government will not necessarily accept nunc pro tunc orders as issued on the nunc pro tunc date. E.g., Fierro v. Reno, 217 F.3d 1 (1st Cir. 2000) (nunc pro tunc order that granted custody to Fierro's father retroactively did not satisfy the custody requirement for automatic citizenship under 8 U.S.C. 1432(a)); Matter of Cariaga, 15 I & N Dec. 716 (1976) (no "retroactive" adoptions for adjustment purposes).  But see Allen v. Brown, 953 F. Supp. 199 (N.D. Ohio 1997) (distinguishing "retroactive" adoptions from "nunc pro tunc" adoptions). Therefore, vacating a conviction, and entering a new plea "nunc pro tunc" will not necessarily be accepted by the immigration authorities or courts as occurring on the nunc pro tunc date.