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HMRC internal manual

Self Assessment Manual

Interest, penalties and surcharge: penalties: appeals against fixed automatic penalties (Action Guide menu)

This guidance refers to tax returns received for 2009-10 and earlier. For further information regarding the new rules for the tax years 2010-11 and later, see SAM61200 onwards.

SAM61062 FAP: reasonable excuse appeal against (Decision Makers Action Guide)
SAM61063 Appeals against non-capping of FAP (Action Guide)