Postal code. Leave it null or 0 if the country does not have postal codes. Mandatory for these countries: AD, AF, AI, AL, AM, AQ, AR, AS, AT, AU, AX, AZ, BA, BB, BD, BE, BG, BL, BM, BN, BQ, BR, BT, BV, BY, CA, CC, CH, CL, CN, CO, CR, CU, CV, CX, CY, CZ, DE, DK, DO, DZ, EC, EE, EG, EH, ES, ET, FI, FK, FM, FO, FR, GA, GB, GE, GF, GG, GI, GL, GP, GR, GS, GT, GU, GW, HM, HN, HR, HT, HU, ID, IE, IL, IM, IN, IO, IQ, IR, IS, IT, JE, JO, JP, KG, KH, KR, KW, KY, KZ, LA, LB, LI, LK, LR, LS, LT, LU, LV, MA, MC, MD, ME, MF, MG, MH, MK, MM, MN, MP, MQ, MT, MV, MX, MY, MZ, NA, NC, NE, NF, NG, NI, NL, NO, NP, NZ, OM, PE, PF, PG, PH, PK, PL, PM, PN, PR, PS, PT, PW, PY, RE, RO, RS, RU, SD, SE, SG, SH, SI, SJ, SK, SM, SN, SS, SV, SX, SZ, TC, TD, TH, TJ, TM, TN, TR, TW, UA, UM, US, UY, UZ, VA, VC, VE, VG, VI, VN, WF, WS, YT, ZA, ZM.
