AL3 postcode district: St Albans and around

AL3 is a postcode district mostly in Hertfordshire, with 955 postcodes in use in 5 sectors. It has postcodes in St Albans, Redbourn and Markyate. It is split between 3 councils: St Albans (763 postcodes), Dacorum (191) and Central Bedfordshire (1). 954 are in Hertfordshire. ONS lists no county for the other 1.

Postcodes in use
955
Sectors
5
Councils
3 councils
Places
3 places

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026. See all our data sources

Every postcode in AL3, by flood risk

Map of every postcode in AL3, by flood risk Of the 955 postcodes in AL3 that ONS places, 8 have a home or business at high risk, 6 are at medium risk at worst, 13 are at low risk at worst, 4 are at very low risk only and 924 are not on the Environment Agency's at-risk list. Places named: St Albans, Hemel Hempstead, Harpenden, Redbourn, Markyate. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 2.5 km. A4147A41 AL3 4AA: not on the flood risk listAL3 4AB: not on the flood risk listAL3 4AE: not on the flood risk listAL3 4AF: not on the flood risk listAL3 4AH: not on the flood risk listAL3 4AL: not on the flood risk listAL3 4AS: not on the flood risk listAL3 4AT: not on the flood risk listAL3 4AW: not on the flood risk listAL3 4AY: not on the flood risk listAL3 4AZ: not on the flood risk listAL3 4BA: not on the flood risk listAL3 4BB: not on the flood risk listAL3 4BD: not on the flood risk listAL3 4BG: not on the flood risk listAL3 4BL: not on the flood risk listAL3 4BQ: not on the flood risk listAL3 4BY: not on the flood risk listAL3 4BZ: not on the flood risk listAL3 4DA: not on the flood risk listAL3 4DE: not on the flood risk listAL3 4DH: not on the flood risk listAL3 4DJ: not on the flood risk listAL3 4DL: not on the flood risk listAL3 4DN: not on the flood risk listAL3 4DP: not on the flood risk listAL3 4DQ: not on the flood risk listAL3 4DR: not on the flood risk listAL3 4DW: not on the flood risk listAL3 4EA: not on the flood risk listAL3 4EB: not on the flood risk listAL3 4ED: not on the flood risk listAL3 4FB: not on the flood risk listAL3 4GB: not on the flood risk listAL3 4GD: not on the flood risk listAL3 4GF: not on the flood risk listAL3 4GG: not on the flood risk listAL3 4GH: not on the flood risk listAL3 4GL: not on the flood risk listAL3 4HA: not on the flood risk listAL3 4HB: not on the flood risk listAL3 4HD: not on the flood risk listAL3 4HE: not on the flood risk listAL3 4HG: not on the flood risk listAL3 4HR: not on the flood risk listAL3 4HW: not on the flood risk listAL3 4HY: not on the flood risk listAL3 4HZ: not on the flood risk listAL3 4JA: not on the flood risk listAL3 4JB: not on the flood risk listAL3 4JE: not on the flood risk listAL3 4JG: not on the flood risk listAL3 4JH: not on the flood risk listAL3 4JJ: not on the flood risk listAL3 4JL: not on the flood risk listAL3 4JN: not on the flood risk listAL3 4JP: not on the flood risk listAL3 4JR: not on the flood risk listAL3 4JS: not on the flood risk listAL3 4JU: not on the flood risk listAL3 4JX: not on the flood risk listAL3 4JY: not on the flood risk listAL3 4LA: not on the flood risk listAL3 4LP: not on the flood risk listAL3 4LR: not on the flood risk listAL3 4LS: not on the flood risk listAL3 4LT: not on the flood risk listAL3 4LU: not on the flood risk listAL3 4LW: not on the flood risk listAL3 4LX: not on the flood risk listAL3 4NA: not on the flood risk listAL3 4ND: not on the flood risk listAL3 4NG: not on the flood risk listAL3 4NH: not on the flood risk listAL3 4NJ: not on the flood risk listAL3 4NR: not on the flood risk listAL3 4PH: not on the flood risk listAL3 4QD: not on the flood risk listAL3 4QG: not on the flood risk listAL3 4QH: not on the flood risk listAL3 4QJ: not on the flood risk listAL3 4QL: not on the flood risk listAL3 4QN: not on the flood risk listAL3 4QT: not on the flood risk listAL3 4QW: not on the flood risk listAL3 4RA: not on the flood risk listAL3 4RF: not on the flood risk listAL3 4RU: not on the flood risk listAL3 4RY: not on the flood risk listAL3 4RZ: not on the flood risk listAL3 4SA: not on the flood risk listAL3 4SL: not on the flood risk listAL3 4SN: not on the flood risk listAL3 4SW: not on the flood risk listAL3 4TA: not on the flood risk listAL3 4TL: not on the flood risk listAL3 4TN: not on the flood risk listAL3 5AB: not on the flood risk listAL3 5AD: not on the flood risk listAL3 5AE: not on the flood risk listAL3 5AH: not on the flood risk listAL3 5AJ: not on the flood risk listAL3 5AN: not on the flood risk listAL3 5AP: not on the flood risk listAL3 5AS: not on the flood risk listAL3 5AT: not on the flood risk listAL3 5AU: not on the flood risk listAL3 5AY: not on the flood risk listAL3 5BA: not on the flood risk listAL3 5BH: not on the flood risk listAL3 5BJ: not on the flood risk listAL3 5BP: not on the flood risk listAL3 5DG: not on the flood risk listAL3 5DL: not on the flood risk listAL3 5DW: not on the flood risk listAL3 5EB: not on the flood risk listAL3 5EJ: not on the flood risk listAL3 5EN: not on the flood risk listAL3 5EP: not on the flood risk listAL3 5EX: not on the flood risk listAL3 5FB: not on the flood risk listAL3 5FD: not on the flood risk listAL3 5FE: not on the flood risk listAL3 5FG: not on the flood risk listAL3 5HE: not on the flood risk listAL3 5HJ: not on the flood risk listAL3 5HN: not on the flood risk listAL3 5HP: not on the flood risk listAL3 5HR: not on the flood risk listAL3 5HS: not on the flood risk listAL3 5HT: not on the flood risk listAL3 5HU: not on the flood risk listAL3 5HX: not on the flood risk listAL3 5HY: not on the flood risk listAL3 5JA: not on the flood risk listAL3 5JB: not on the flood risk listAL3 5JH: not on the flood risk listAL3 5JJ: not on the flood risk listAL3 5JR: not on the flood risk listAL3 5JU: not on the flood risk listAL3 5JY: not on the flood risk listAL3 5JZ: not on the flood risk listAL3 5LA: not on the flood risk listAL3 5LD: not on the flood risk listAL3 5LE: not on the flood risk listAL3 5LF: not on the flood risk listAL3 5LG: not on the flood risk listAL3 5LH: not on the flood risk listAL3 5LJ: not on the flood risk listAL3 5LN: not on the flood risk listAL3 5LP: not on the flood risk listAL3 5LR: not on the flood risk listAL3 5LX: not on the flood risk listAL3 5NE: not on the flood risk listAL3 5NG: not on the flood risk listAL3 5NJ: not on the flood risk listAL3 5NZ: not on the flood risk listAL3 5PA: not on the flood risk listAL3 5PD: not on the flood risk listAL3 5PE: not on the flood risk listAL3 5PJ: not on the flood risk listAL3 5PN: not on the flood risk listAL3 5PP: not on the flood risk listAL3 5PR: not on the flood risk listAL3 5PS: not on the flood risk listAL3 5QG: not on the flood risk listAL3 5QH: not on the flood risk listAL3 5QY: not on the flood risk listAL3 5RB: not on the flood risk listAL3 5RG: not on the flood risk listAL3 5RH: not on the flood risk listAL3 5RN: not on the flood risk listAL3 5RP: not on the flood risk listAL3 5RR: not on the flood risk listAL3 5RS: not on the flood risk listAL3 5RT: not on the flood risk listAL3 5RW: not on the flood risk listAL3 5RX: not on the flood risk listAL3 5SA: not on the flood risk listAL3 5SB: not on the flood risk listAL3 5SD: not on the flood risk listAL3 5SG: not on the flood risk listAL3 5SS: not on the flood risk listAL3 5SX: not on the flood risk listAL3 5SY: not on the flood risk listAL3 5TA: not on the flood risk listAL3 5TD: not on the flood risk listAL3 5TF: not on the flood risk listAL3 5TH: not on the flood risk listAL3 5TJ: not on the flood risk listAL3 5TL: not on the flood risk listAL3 5TN: not on the flood risk listAL3 5TP: not on the flood risk listAL3 5TS: not on the flood risk listAL3 5TT: not on the flood risk listAL3 5TW: not on the flood risk listAL3 5TX: not on the flood risk listAL3 5TZ: not on the flood risk listAL3 5UB: not on the flood risk listAL3 5UD: not on the flood risk listAL3 5UH: not on the flood risk listAL3 5UJ: not on the flood risk listAL3 5UL: not on the flood risk listAL3 5UP: not on the flood risk listAL3 5UW: not on the flood risk listAL3 5XA: not on the flood risk listAL3 6AA: not on the flood risk listAL3 6AD: not on the flood risk listAL3 6AE: not on the flood risk listAL3 6AF: not on the flood risk listAL3 6AG: not on the flood risk listAL3 6AH: not on the flood risk listAL3 6AL: not on the flood risk listAL3 6AN: not on the flood risk listAL3 6AP: not on the flood risk listAL3 6AQ: not on the flood risk listAL3 6AR: not on the flood risk listAL3 6AS: not on the flood risk listAL3 6AW: not on the flood risk listAL3 6AX: not on the flood risk listAL3 6AY: not on the flood risk listAL3 6BB: not on the flood risk listAL3 6BE: not on the flood risk listAL3 6BG: not on the flood risk listAL3 6BJ: not on the flood risk listAL3 6BL: not on the flood risk listAL3 6BN: not on the flood risk listAL3 6BP: not on the flood risk listAL3 6BS: not on the flood risk listAL3 6BT: not on the flood risk listAL3 6BU: not on the flood risk listAL3 6BY: not on the flood risk listAL3 6BZ: not on the flood risk listAL3 6DA: not on the flood risk listAL3 6DB: not on the flood risk listAL3 6DD: not on the flood risk listAL3 6DF: not on the flood risk listAL3 6DG: not on the flood risk listAL3 6DJ: not on the flood risk listAL3 6DL: not on the flood risk listAL3 6DP: not on the flood risk listAL3 6DQ: not on the flood risk listAL3 6DR: not on the flood risk listAL3 6DU: not on the flood risk listAL3 6DX: not on the flood risk listAL3 6DY: not on the flood risk listAL3 6DZ: not on the flood risk listAL3 6EA: not on the flood risk listAL3 6EB: not on the flood risk listAL3 6EF: not on the flood risk listAL3 6EG: not on the flood risk listAL3 6EJ: not on the flood risk listAL3 6EL: not on the flood risk listAL3 6EN: not on the flood risk listAL3 6EP: not on the flood risk listAL3 6EQ: not on the flood risk listAL3 6ER: not on the flood risk listAL3 6ES: not on the flood risk listAL3 6EU: not on the flood risk listAL3 6EW: not on the flood risk listAL3 6EZ: not on the flood risk listAL3 6GY: not on the flood risk listAL3 6HA: not on the flood risk listAL3 6HB: not on the flood risk listAL3 6HE: not on the flood risk listAL3 6HJ: not on the flood risk listAL3 6HN: not on the flood risk listAL3 6HP: not on the flood risk listAL3 6HQ: not on the flood risk listAL3 6HR: not on the flood risk listAL3 6HS: not on the flood risk listAL3 6HX: not on the flood risk listAL3 6JB: not on the flood risk listAL3 6JE: not on the flood risk listAL3 6JF: not on the flood risk listAL3 6JG: not on the flood risk listAL3 6JH: not on the flood risk listAL3 6JJ: not on the flood risk listAL3 6JL: not on the flood risk listAL3 6JN: not on the flood risk listAL3 6JP: not on the flood risk listAL3 6JQ: not on the flood risk listAL3 6JR: not on the flood risk listAL3 6JS: not on the flood risk listAL3 6JU: not on the flood risk listAL3 6JW: not on the flood risk listAL3 6JX: not on the flood risk listAL3 6JY: not on the flood risk listAL3 6JZ: not on the flood risk listAL3 6LA: not on the flood risk listAL3 6LG: not on the flood risk listAL3 6LH: not on the flood risk listAL3 6LJ: not on the flood risk listAL3 6LN: not on the flood risk listAL3 6LP: not on the flood risk listAL3 6LQ: not on the flood risk listAL3 6LS: not on the flood risk listAL3 6LW: not on the flood risk listAL3 6LZ: not on the flood risk listAL3 6NB: not on the flood risk listAL3 6NL: not on the flood risk listAL3 6NP: not on the flood risk listAL3 6NQ: not on the flood risk listAL3 6NR: not on the flood risk listAL3 6NX: not on the flood risk listAL3 6PA: not on the flood risk listAL3 6RA: not on the flood risk listAL3 6RD: not on the flood risk listAL3 6RE: not on the flood risk listAL3 6RF: not on the flood risk listAL3 6RG: not on the flood risk listAL3 6RH: not on the flood risk listAL3 6RJ: not on the flood risk listAL3 6RL: not on the flood risk listAL3 6RN: not on the flood risk listAL3 6RP: not on the flood risk listAL3 6RQ: not on the flood risk listAL3 6RR: not on the flood risk listAL3 6RS: not on the flood risk listAL3 6RW: not on the flood risk listAL3 6XT: not on the flood risk listAL3 6XZ: not on the flood risk listAL3 7AA: not on the flood risk listAL3 7AB: not on the flood risk listAL3 7AD: not on the flood risk listAL3 7AE: not on the flood risk listAL3 7AF: not on the flood risk listAL3 7AG: not on the flood risk listAL3 7AJ: not on the flood risk listAL3 7AL: not on the flood risk listAL3 7AN: not on the flood risk listAL3 7AP: not on the flood risk listAL3 7AQ: not on the flood risk listAL3 7AR: not on the flood risk listAL3 7AS: not on the flood risk listAL3 7AT: not on the flood risk listAL3 7AU: not on the flood risk listAL3 7AW: not on the flood risk listAL3 7BA: not on the flood risk listAL3 7BB: not on the flood risk listAL3 7BD: not on the flood risk listAL3 7BE: not on the flood risk listAL3 7BF: not on the flood risk listAL3 7BG: not on the flood risk listAL3 7BJ: not on the flood risk listAL3 7BL: not on the flood risk listAL3 7BN: not on the flood risk listAL3 7BS: not on the flood risk listAL3 7BU: not on the flood risk listAL3 7BX: not on the flood risk listAL3 7BY: not on the flood risk listAL3 7BZ: not on the flood risk listAL3 7DA: not on the flood risk listAL3 7DB: not on the flood risk listAL3 7DD: not on the flood risk listAL3 7DE: not on the flood risk listAL3 7DF: not on the flood risk listAL3 7DH: not on the flood risk listAL3 7DJ: not on the flood risk listAL3 7DN: not on the flood risk listAL3 7DP: not on the flood risk listAL3 7DS: not on the flood risk listAL3 7DU: not on the flood risk listAL3 7DW: not on the flood risk listAL3 7DZ: not on the flood risk listAL3 7EA: not on the flood risk listAL3 7EB: not on the flood risk listAL3 7EL: not on the flood risk listAL3 7EN: not on the flood risk listAL3 7EP: not on the flood risk listAL3 7ER: not on the flood risk listAL3 7ES: not on the flood risk listAL3 7ET: not on the flood risk listAL3 7EX: not on the flood risk listAL3 7EZ: not on the flood risk listAL3 7FA: not on the flood risk listAL3 7FB: not on the flood risk listAL3 7FD: not on the flood risk listAL3 7GA: not on the flood risk listAL3 7GF: not on the flood risk listAL3 7GH: not on the flood risk listAL3 7HA: not on the flood risk listAL3 7HB: not on the flood risk listAL3 7HE: not on the flood risk listAL3 7HF: not on the flood risk listAL3 7HP: not on the flood risk listAL3 7HQ: not on the flood risk listAL3 7HR: not on the flood risk listAL3 7HW: not on the flood risk listAL3 7HY: not on the flood risk listAL3 7HZ: not on the flood risk listAL3 7JA: not on the flood risk listAL3 7JB: not on the flood risk listAL3 7JD: not on the flood risk listAL3 7JE: not on the flood risk listAL3 7JF: not on the flood risk listAL3 7JG: not on the flood risk listAL3 7JH: not on the flood risk listAL3 7JJ: not on the flood risk listAL3 7JL: not on the flood risk listAL3 7JR: not on the flood risk listAL3 7JX: not on the flood risk listAL3 7JZ: not on the flood risk listAL3 7LL: not on the flood risk listAL3 7LR: not on the flood risk listAL3 7LS: not on the flood risk listAL3 7LU: not on the flood risk listAL3 7LY: not on the flood risk listAL3 7NB: not on the flood risk listAL3 7NG: not on the flood risk listAL3 7NJ: not on the flood risk listAL3 7NN: not on the flood risk listAL3 7NP: not on the flood risk listAL3 7NQ: not on the flood risk listAL3 7NU: not on the flood risk listAL3 7NX: not on the flood risk listAL3 7PB: not on the flood risk listAL3 7PE: not on the flood risk listAL3 7PF: not on the flood risk listAL3 7PG: not on the flood risk listAL3 7PH: not on the flood risk listAL3 7PJ: not on the flood risk listAL3 7PN: not on the flood risk listAL3 7PP: not on the flood risk listAL3 7PR: not on the flood risk listAL3 7PS: not on the flood risk listAL3 7PT: not on the flood risk listAL3 7PU: not on the flood risk listAL3 7PX: not on the flood risk listAL3 7PY: not on the flood risk listAL3 7PZ: not on the flood risk listAL3 7QA: not on the flood risk listAL3 7QB: not on the flood risk listAL3 7QE: not on the flood risk listAL3 7QN: not on the flood risk listAL3 7QQ: not on the flood risk listAL3 7RG: not on the flood risk listAL3 7RQ: not on the flood risk listAL3 7SA: not on the flood risk listAL3 8AA: not on the flood risk listAL3 8AB: not on the flood risk listAL3 8AD: not on the flood risk listAL3 8AE: not on the flood risk listAL3 8AF: not on the flood risk listAL3 8AG: not on the flood risk listAL3 8AH: not on the flood risk listAL3 8AJ: not on the flood risk listAL3 8AL: not on the flood risk listAL3 8AN: not on the flood risk listAL3 8AP: not on the flood risk listAL3 8AQ: not on the flood risk listAL3 8AR: not on the flood risk listAL3 8AS: not on the flood risk listAL3 8AT: not on the flood risk listAL3 8AU: not on the flood risk listAL3 8AW: not on the flood risk listAL3 8AX: not on the flood risk listAL3 8AY: not on the flood risk listAL3 8AZ: not on the flood risk listAL3 8BA: not on the flood risk listAL3 8BB: not on the flood risk listAL3 8BD: not on the flood risk listAL3 8BH: not on the flood risk listAL3 8BL: not on the flood risk listAL3 8BN: not on the flood risk listAL3 8BP: not on the flood risk listAL3 8BS: not on the flood risk listAL3 8BU: not on the flood risk listAL3 8BW: not on the flood risk listAL3 8BY: not on the flood risk listAL3 8DB: not on the flood risk listAL3 8DE: not on the flood risk listAL3 8DF: not on the flood risk listAL3 8DG: not on the flood risk listAL3 8DH: not on the flood risk listAL3 8DJ: not on the flood risk listAL3 8DL: not on the flood risk listAL3 8DN: not on the flood risk listAL3 8DP: not on the flood risk listAL3 8DR: not on the flood risk listAL3 8DU: not on the flood risk listAL3 8DW: not on the flood risk listAL3 8DX: not on the flood risk listAL3 8EB: not on the flood risk listAL3 8ED: not on the flood risk listAL3 8EE: not on the flood risk listAL3 8EG: not on the flood risk listAL3 8EL: not on the flood risk listAL3 8EP: not on the flood risk listAL3 8ER: not on the flood risk listAL3 8ES: not on the flood risk listAL3 8ET: not on the flood risk listAL3 8EU: not on the flood risk listAL3 8EW: not on the flood risk listAL3 8EY: not on the flood risk listAL3 8FL: not on the flood risk listAL3 8HD: not on the flood risk listAL3 8HG: not on the flood risk listAL3 8HH: not on the flood risk listAL3 8HJ: not on the flood risk listAL3 8HL: not on the flood risk listAL3 8HR: not on the flood risk listAL3 8HS: not on the flood risk listAL3 8HT: not on the flood risk listAL3 8HU: not on the flood risk listAL3 8HW: not on the flood risk listAL3 8HX: not on the flood risk listAL3 8HY: not on the flood risk listAL3 8JD: not on the flood risk listAL3 8JE: not on the flood risk listAL3 8JF: not on the flood risk listAL3 8JJ: not on the flood risk listAL3 8JS: not on the flood risk listAL3 8JT: not on the flood risk listAL3 8JX: not on the flood risk listAL3 8LA: not on the flood risk listAL3 8LL: not on the flood risk listAL3 8LN: not on the flood risk listAL3 8LP: not on the flood risk listAL3 8LR: not on the flood risk listAL3 8LS: not on the flood risk listAL3 8LT: not on the flood risk listAL3 8LW: not on the flood risk listAL3 8NB: not on the flood risk listAL3 8NE: not on the flood risk listAL3 8NQ: not on the flood risk listAL3 8NW: not on the flood risk listAL3 8PD: not on the flood risk listAL3 8PE: not on the flood risk listAL3 8PG: not on the flood risk listAL3 8PQ: not on the flood risk listAL3 8PR: not on the flood risk listAL3 8PT: not on the flood risk listAL3 8PW: not on the flood risk listAL3 8PX: not on the flood risk listAL3 8PZ: not on the flood risk listAL3 8QA: not on the flood risk listAL3 8QB: not on the flood risk listAL3 8QD: not on the flood risk listAL3 8QE: not on the flood risk listAL3 8QF: not on the flood risk listAL3 8QG: not on the flood risk listAL3 8QH: not on the flood risk listAL3 8QJ: not on the flood risk listAL3 8QL: not on the flood risk listAL3 8QQ: not on the flood risk listAL3 8QU: not on the flood risk listAL3 8RB: not on the flood risk listAL3 8RE: not on the flood risk listAL3 8RF: not on the flood risk listAL3 8RG: not on the flood risk listAL3 8RH: not on the flood risk listAL3 8RJ: not on the flood risk listAL3 8RL: not on the flood risk listAL3 8RN: not on the flood risk listAL3 8RQ: not on the flood risk listAL3 8RR: not on the flood risk listAL3 8RS: not on the flood risk listAL3 8RU: not on the flood risk listAL3 8RW: not on the flood risk listAL3 4SD: very low flood risk onlyAL3 8JR: very low flood risk onlyAL3 4SF: low flood risk at worstAL3 4SG: low flood risk at worstAL3 4SP: low flood risk at worstAL3 7QG: low flood risk at worstAL3 7LG: low flood risk at worstAL3 7LT: low flood risk at worstAL3 7PD: low flood risk at worstAL3 8EX: low flood risk at worstAL3 8JL: low flood risk at worstAL3 8PL: low flood risk at worstAL3 8PY: low flood risk at worstAL3 8LG: medium flood risk at worstAL3 8JG: medium flood risk at worstAL3 8JP: medium flood risk at worstAL3 8LY: medium flood risk at worstAL3 8NL: medium flood risk at worstAL3 4HJ: high flood riskAL3 4SJ: high flood riskAL3 6LB: high flood riskAL3 7LA: high flood riskAL3 7NH: high flood riskAL3 8JH: high flood riskAL3 8HA: high flood riskAL3 8HB: high flood risk St AlbansHemel HempsteadHarpendenRedbournMarkyate Map of every postcode in AL3, by flood risk Of the 955 postcodes in AL3 that ONS places, 8 have a home or business at high risk, 6 are at medium risk at worst, 13 are at low risk at worst, 4 are at very low risk only and 924 are not on the Environment Agency's at-risk list. Places named: St Albans, Harpenden, Redbourn, Markyate. Drawn over roads, rivers and built-up areas. North is up; the scale bar is 2.5 km. St AlbansHarpendenRedbournMarkyate
  • A home or business at high risk: 8
  • At medium risk at worst: 6
  • At low risk at worst: 13
  • At very low risk only: 4
  • Not on the at-risk list: 924

Of the 955 postcodes in AL3 that ONS places, 8 have a home or business at high risk, 6 are at medium risk at worst, 13 are at low risk at worst, 4 are at very low risk only and 924 are not on the Environment Agency's at-risk list.

Each mark is a postcode's centre point as ONS gives it, not a building. Press one to see its postcode and open its page. No boundary is drawn. Where marks overlap, the one first in the key is drawn; the counts include every postcode.

The middle of its postcodes: latitude 51.7805, longitude -0.3777. Open this area on OpenStreetMap

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026, the centre point of each postcode; flood risk: Environment Agency, published 6 July 2026; roads, rivers and built-up areas: Contains OS data © Crown copyright and database right 2026. Drawn by us. Street map: Ordnance Survey, OS Open Zoomstack, Open Government Licence v3.0, drawn with MapLibre. How we use them

The postcodes at high risk

Beside each: how many of its homes and businesses the Environment Agency puts at that risk.

AL3 8JH7 at high riskAL3 7NH2 at high riskAL3 7LA2 at high riskAL3 4SJ1 at high riskAL3 6LB1 at high riskAL3 4HJ1 at high riskAL3 8HA1 at high riskAL3 8HB1 at high risk

What broadband can you get in AL3?

Ofcom reports on 951 of the 955 postcodes in AL3. At 684 of them every home and business can get gigabit broadband, and at 1 some cannot get decent broadband (10 Mbit/s).

Postcodes where every home can get gigabit684 of 951
Postcodes where every home can get superfast832 of 951
Postcodes where some cannot get decent broadband1 of 951

Ofcom gives each postcode's share of homes and businesses, not how many there are, so these count postcodes. Each postcode page has its own figures. A provider's checker answers for one address.

Check one address on Ofcom's checker

Source: Ofcom, Connected Nations, Spring 2026, data for January 2026, Open Government Licence v3.0. How we use it

Is AL3 at risk of flooding?

31 of the 955 postcodes in AL3 have a home or business in an area at risk of flooding from rivers or the sea, the Environment Agency says. At those, it puts 50 homes and businesses in an area at high or medium risk.

Homes and businesses in an area at risk, at 31 of 955 postcodes High: 16Medium: 34Low: 70Very low: 86

High: 3.3% or more a year (1 in 30). Medium: 1% to 3.3% a year. Low: 0.1% to 1% a year. Very low: under 0.1% a year (1 in 1,000). Each band is the chance of flooding in any one year.

Homes and businesses in an area at risk of flooding from rivers or the sea, as the Environment Agency counts them, added up over the postcodes. It is for the land, not each building, and leaves out surface water, groundwater and sewers. Each postcode page has its own figures and its flood warning areas.

Source: Environment Agency, Risk of Flooding from Rivers and Sea (postcodes in areas at risk), published 6 July 2026, Open Government Licence v3.0. How we use it

What do homes sell for in AL3?

Homes in AL3 sold for a typical £618,000 in the 12 months to August 2026, across 309 sales, down 4.9% on the 12 months before, HM Land Registry's figures show.

£618,000 typical price, the 12 months to August 2026
£650,000 12 months to August 2025
▼ down 4.9% on the 12 months before
  • Detached £910,000 57 sales
  • Semi-detached £650,000 80 sales
  • Terraced £599,000 134 sales
  • Flat or maisonette £343,750 38 sales

Each bar is that kind's typical price, against the most expensive kind here.

Standard sales of homes at market value. A typical price is the median, the middle sale. Sales take weeks to be registered, so the last month or two are incomplete. Each postcode page gives the figure for its own postcode sector.

Source: HM Land Registry Price Paid Data, files dated 28 September 2026. Contains HM Land Registry data © Crown copyright and database right 2021. This data is licensed under the Open Government Licence v3.0. How we use it

Postcodes in AL3

Pick a sector, then a postcode. A sector is the district plus the next digit.

AL3 4186 postcodesAL3 5232 postcodesAL3 6162 postcodesAL3 7184 postcodesAL3 8191 postcodes
UK postcode format explained

Places in AL3

Towns and villages with postcodes in AL3, and how many each has here.

St Albans postcodes,530Redbourn postcodes,153Markyate postcodes,95

Who covers AL3

How many of the district's postcodes in use fall under each council, constituency and police force area.

Councils

What council am I in?

Constituencies

  • St Albans535
  • Harpenden and Berkhamsted419
  • Luton South and South Bedfordshire1

Police force areas

  • Hertfordshire954
  • Bedfordshire1

Next to AL3

AL2 postcode district AL4 postcode district All AL districts St Albans postcodes

"Next to" is by number: the districts before and after AL3 in the AL area.

Check a postcode

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