Error detection and correction in RNS has received considerable attention in literature. This was considered to be necessary in ROM based designs where some faults may occur which may be corrected by reconfiguring or bypassing the faulty device using additional residues corresponding to additional moduli. These additional moduli are termed as redundant moduli. The errors evidently can occur in the residues or redundant residues. These redundant residues are mandatory for error detection and correction. Techniques for error detection and correction are considered in detail in this Chapter. The possibility of scaling and residue error correction in a single hardware also is considered.